Sample records for extracted ion beam

An apparatus (900) and methods are disclosed for ionbeamextraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fracti...

Highlights: ► A RF based negative hydrogen ionbeam test bed has been set up at IPR, India. ► Ion source has been successfully commissioned and three campaigns of plasma production have been carried out. ► Extraction system (35 kV) has been installed and commissioning has been initiated. Negative ionbeamextraction is immediate milestone. -- Abstract: The RF based single driver −ve ion source experiment test bed ROBIN (Replica Of BATMAN like source in INDIA) has been set up at Institute for Plasma Research (IPR), India in a technical collaboration with IPP, Garching, Germany. A hydrogen plasma of density 5 × 10 12 cm −3 is expected in driver region of ROBIN by launching 100 kW RF power into the driver by 1 MHz RF generator. The cesiated source is expected to deliver a hydrogen negative ionbeam of 10 A at 35 kV with a current density of 35 mA/cm 2 as observed in BATMAN. In first phase operation of the ROBIN ion source, a hydrogen plasma has been successfully generated (without extraction system) by coupling 80 kW RF input power through a matching network with high power factor (cos θ > 0.8) and different plasma parameters have been measured using Langmuir probes and emission spectroscopy. The plasma density of 2.5 × 10 11 cm −3 has been measured in the extraction region of ROBIN. For negative hydrogen ionbeamextraction in second phase operation, extraction system has been assembled and installed with ion source on the vacuum vessel. The source shall be first operated in volume mode for negative ionbeamextraction. The commissioning of the source with high voltage power supply has been initiated

The strict application of conventional extraction techniques of ionbeams from a plasma source is characterized by a natural intensity limit determined by space charge.The extracted current may be enhanced far beyond this limit by neutralizing the space charge of the extractedions in the first extraction gap of the source with electrons injected from the opposite side. The transverse and longitudinal emittances of a neutralized ionbeam, hence its brightness, are preserved. Results of beam compensation experiments, which have been carried out with a laser ion source, are resumed for proposing a general scheme of neutralizing ion sources and their adjacent low-energy beam transport channels with electron beams. Many technical applications of high-mass ionbeam neutralization technology may be identified: the enhancement of ion source output for injection into high-intensity, low-and high-energy accelerators, or ion thrusters in space technology, for the neutral beams needed for plasma heating of magnetic conf...

Depending on the specific type of ion source, the ionbeam is extracted either from an electrode surface or from a plasma. There is always an interface between the (almost) space charge compensated ion source plasma, and the extraction region in which the full space charge is influencing the ionbeam itself. After extraction, the ionbeam is to be transported towards an accelerating structure in most cases. For lower intensities, this transport can be done without space charge compensation. However, if space charge is not negligible, the positive charge of the ionbeam will attract electrons, which will compensate the space charge, at least partially. The final degree of Space Charge Compensation (SCC) will depend on different properties, like the ratio of generation rate of secondary particles and their loss rate, or the fact whether the ionbeam is pulsed or continuous. In sections of the beam line, where the ionbeam is drifting, a pure electrostatic plasma will develop, whereas in magnetic elements, these space charge compensating electrons become magnetized. The transport section will provide a series of different plasma conditions with different properties. Different measurement tools to investigate the degree of space charge compensation will be described, as well as computational methods for the simulation of ionbeams with partial space charge compensation

In Korea Multipurpose Accelerator Complex (KOMAC), we have started ionbeam service in the new beam utilization building since March this year. For various ionbeam irradiation services, we are developed implanters such as metal (150keV/1mA), gaseous (200keV/5mA) and high current ionbeam facility (20keV/150mA). One of the new one is a vertical type ionbeam facility without acceleration tube (60keV/20mA) which is easy to install the sample. After the installation is complete, it is where you are studying the optimal ionbeamextraction process. Detailed experimental results will be presented. Vertical Type IonBeam Facility without acceleration tube of 60keV 20mA class was installed. We successfully extracted 60keV 20mA using Duo- PiGatron Ion source for Vertical Type IonBeam Facility. Use the BPM and Faraday-cup, is being studied the optimum conditions of ionbeamextraction.

In this work a theoretical and computational study on the space charge dominated beamsextracted from a plasma ion source through a spherical and planer electrode is simulated and optimized. The influence of some electrode parameters: axial position, electrode diameter, material and shape; on ion current extracted from a plasma source; were investigated and compared. The optimum values and conditions of the curvature of the plasma boundary, angular divergence, perveance, and the extraction gap were optimized to extract a high quality beams. It has shown that for a planar electrode system there is usually a minimum for optimum perveance versus angular divergence at about ? 0.6 for corresponding aspect ratios. This was assured by experimental data. The appropriate spherical electrode system focus the beam to a minimum value located at a distance equal to the focal length of the spherical extraction electrode.

Electron cyclotron resonance ion source with quasi-gas-dynamic regime of plasma confinement (ReGIS), constructed at the Institute of Applied Physics, Russia, provides opportunities for extracting intense and high-brightness multicharged ionbeams. Despite the short plasma lifetime in a magnetic trap of a ReGIS, the degree of multiple ionization may be significantly enhanced by the increase in power and frequency of the applied microwave radiation. The present work is focused on studying the intense beam quality of this source by the pepper-pot method. A single beamlet emittance measured by the pepper-pot method was found to be ∼70 π mm mrad, and the total extractedbeam current obtained at 14 kV extraction voltage was ∼25 mA. The results of the numerical simulations of ionbeamextraction are found to be in good agreement with experimental data

A metal ion source of magnetron magnetic field geometry has been designed and operated with a Cu hollow target. Radio frequency power at 13.56 MHz is directly supplied to the hollow target to maintain plasma discharge and induce self-bias to the target for sputtering. The extraction of positive and negative Cu ionbeams have been tested. The ionbeam current ratio of Cu{sup +} to Ar{sup +} has reached up to 140% when Ar was used as the discharge support gas. Cu{sup −} ionbeam was observed at 50 W RF discharge power and at a higher Ar gas pressure in the ion source. Improvement of poor RF power matching and suppression of electron current is indispensable for a stable Cu{sup −} ionbeam production from the source.

A plasma grid structure was installed to a Bernas-type ion source used for ion implantation equipment. A negative hydrogen (H{sup −}) ionbeam was extracted by an AC driven ion source by adjusting the bias to the plasma grid. The extracted electron current was reduced by positively biasing the plasma grid, while an optimum plasma grid bias voltage for negative ionbeamextraction was found to be positive 3 V with respect to the arc chamber. Source operations with AC cathode heating show extraction characteristics almost identical to that with DC cathode heating, except a minute increase in H{sup −} current at higher frequency of cathode heating current.

A portable test bench is described, which was designed to check ion sources, ionbeamextraction and focusing systems before its use in a 600 KeV Cockcroft-Walton accelerator. The vacuum possibilities of the system are specially analyzed in connection with its particular use. The whole can be considered as a portable accelerator of low energy (50 keV). (Author)

-ECR plasma source [3] with transversal magnetic filter for electron temperature control. 12 ECR plasma cells are placed 7.5 cm apart on the top of a cubic chamber 40x40x40 cm3. Each cell can be controlled independently by tuning the injected microwave power. The discharge is operated at pressures below 1 m......Positive or negative ionbeamsextracted from plasma are used in a large variety of surface functionalization techniques such as implantation, etching, surface activation, passivation or oxidation. Of particular importance is the surface treatment of materials sensitive to direct plasma exposure...... due to high heath fluxes, the controllability of the ion incidence angle, and charge accumulation when treating insulating materials. Despite of a large variety of plasma sources available for ionbeamextraction, there is a clear need for new extraction mechanisms that can make available ionbeams...

In all accelerator projects, the low energy part of the accelerator has to be carefully optimized to match the beam characteristic requirements of the higher energy parts. Since 1994 with the beginning of the Injector of Protons for High Intensity (IPHI) project and Source of Light Ions with High Intensities (SILHI) electron cyclotron resonance (ECR) ion source development at CEA/Saclay, we are using a set of two-dimensional (2D) codes for extraction system optimization (AXCEL, OPERA-2D) and beam transport (MULTIPART). The 95 keV SILHI extraction system optimization has largely increased the extracted current, and improved the beam line transmission. From these good results, a 130 mA D + extraction system for the International Fusion Material Irradiation Facility project has been designed in the same way as SILHI one. We are also now involved in the SPIRAL 2 project for the building of a 40 keV D + ECR ion source, continuously tunable from 0.1 to 5 mA, for which a special four-electrode extraction system has been studied. In this article we will describe the 2D design process and present the different extraction geometries and beam characteristics. Simulation results of SILHI H + beam emittance will be compared with experimental measurements

Extraction of high quality space-charge-dominated ionbeams from plasma ion sources constitutes an optimization problem centered about finding an optimal concave plasma emission boundary that minimizes half-angular divergence for a given charge state, independent of the presence or lack thereof of a magnetic field in the extraction region. The curvature of the emission boundary acts to converge/diverge the low velocity beam during extraction. Beams of highest quality are extracted whenever the half-angular divergence, ω, is minimized. Under minimum half-angular divergence conditions, the plasma emission boundary has an optimum curvature and the perveance, P, current density, j+ext, and extraction gap, d, have optimum values for a given charge state, q. Optimum values for each of the independent variables (P, j+ext and d) are found to be in close agreement with those derived from elementary analytical theory for extraction with a simple two-electrode extraction system, independent of the presence of a magnetic field. The magnetic field only increases the emittances of beams through additional aberrational effects caused by increased angular divergences through coupling of the longitudinal to the transverse velocity components of particles as they pass though the mirror region of the electron cyclotron resonance (ECR) ion source. This article reviews the underlying theory of elementary extraction optics and presents results derived from simulation studies of extraction of space-charge dominated heavy-ionbeams of varying mass, charge state, and intensity from an ECR ion source with emphasis on magnetic field induced effects.

Extraction of high quality space-charge-dominated ionbeams from plasma ion sources constitutes an optimization problem centered about finding an optimal concave plasma emission boundary that minimizes half-angular divergence for a given charge state, independent of the presence or lack thereof of a magnetic field in the extraction region. The curvature of the emission boundary acts to converge/diverge the low velocity beam during extraction. Beams of highest quality are extracted whenever the half-angular divergence, ω, is minimized. Under minimum half-angular divergence conditions, the plasma emission boundary has an optimum curvature and the perveance, P, current density, j +ext , and extraction gap, d, have optimum values for a given charge state, q. Optimum values for each of the independent variables (P, j +ext and d) are found to be in close agreement with those derived from elementary analytical theory for extraction with a simple two-electrode extraction system, independent of the presence of a magnetic field. The magnetic field only increases the emittances of beams through additional aberrational effects caused by increased angular divergences through coupling of the longitudinal to the transverse velocity components of particles as they pass though the mirror region of the electron cyclotron resonance (ECR) ion source. This article reviews the underlying theory of elementary extraction optics and presents results derived from simulation studies of extraction of space-charge dominated heavy-ionbeams of varying mass, charge state, and intensity from an ECR ion source with emphasis on magnetic field induced effects

Designing optimized ECR (electron cyclotron resonance) ionbeam sources can be streamlined by the accurate simulation of beam optical properties in order to predict ionextraction behavior. The complexity of these models, however, can make PIC-based simulations time-consuming. In this paper, we first describe a simple kinetic plasma finite element simulation of extraction of a proton beam from a permanent magnet hexapole ECR ion source. Second, we analyze the influence of secondary electrons generated by ion collisions in the residual gas on the space charge of a proton beam of a dual-solenoid ECR ion source. The finite element method (FEM) offers a fast modeling environment, allowing analysis of ionbeam behavior under conditions of varying current density, electrode potential, and gas pressure. The new version of SCALA/TOSCA v14 permits the making of simulations in tens of minutes to a few hours on standard computer platforms without the need of particle-in-cell methods. The paper is followed by the slides of the presentation. (authors)

This work presents the design and development of a simple ion source, the associated ionextraction optics, and the beam transport of a low-energy and high-current proton accelerator. In its actual version, the ion source can deliver positive proton currents up to 100 mA. This rather high beam current is achieved by adding a small ionization chamber between the discharge chamber containing the filament and the extraction electrode of the ion source. Different parameters of the ion source and the injection beam line are evaluated by means of computer simulations to optimize the beam production and transmission

A comprehensive study of beam formation and beam transport has been initiated in order to improve the performance of the CERN heavy ion injector, Linac3. As part of this study, the ionbeamextraction system of the CERN GTS-LHC 14.5 GHz Electron Cyclotron Resonance Ion Source (ECRIS) has been modelled with the ion optical code IBSimu. The simulations predict self-consistently the triangular and hollow beam structures which are often observed experimentally with ECRIS ionbeams. The model is used to investigate the performance of the current extraction system and provides a basis for possible future improvements. In addition, the extraction simulation provides a more realistic representation of the initial beam properties for the beam transport simulations, which aim to identify the performance bottle necks along the Linac3 low energy beam transport. The results of beamextraction simulations with Pb and Ar ionbeams from the GTS-LHC will be presented and compared with experimental observations.

The two-dimensional code and the three-dimensional code have been developed to study the physical features of the ionbeams in the extraction and acceleration stages. By using the two-dimensional code, the design of first electrode(plasma grid) is examined in regard to the beam divergence. In the computational studies by using the three-dimensional code, the axis-off model of ionbeam is investigated. It is found that the deflection angle of ionbeam is proportional to the gap displacement of the electrodes. (author)

For effective evaporation of refractory metal, electron beam is found to be most suitable vapour generator source. Using electron beam, high throughput laser based purification processes are carried out. But due to highly concentrated electron beam, the vapour gets ionised and these ions lead to dilution of the pure product of laser based separation process. To estimate the concentration of these ions and extraction potential requirement to remove these ions from vapour stream, experiments have been conducted using aluminium as evaporant. The aluminium ingots were placed in water cooled copper crucible. Inserts were used to hold the evaporant, in order to attain higher number density in the vapour processing zone and also for confining the liquid metal. Parametric studies with beam power, number density and extraction potential were conducted. In this paper we discuss the trend of the generation of thermal ions and electrostatic field requirement for extraction.

Full Text Available High-current Cu^{+} ionbeams were extracted from a laser-produced plasma using a pulsed high-voltage multiaperture diode driven by an induction cavity. The amplitude and the duration of the extraction voltage were 130 kV and 450 ns, respectively. During the extraction, explosive beam divergence due to the strong space-charge force was suppressed by the focusing action of the gap between concentric hemispheres. Modulation of the extractedbeam flux due to the plasma prefill in the gap has been eliminated by using a biased control grid put on the anode holes. By means of this extraction scheme we obtained a rectangular beam pulse with a rise time as short as ≈100 ns. The beam current behind the cathode was limited to ≈0.1 A, owing to space-charge effects, as well as to poor geometrical transmission through the cathode sphere. From the measurement of the extractedbeam current density distribution along the beam axis and the beam profile measurement, we found a beam waist slightly downstream of the spherical center of the diode structure. The measured beam behavior was consistent with numerical results obtained via a 3D particle code. No serious degradation of the beam emittance was observed for the grid-controlled extraction scheme.

HEDP applications require high line charge density ionbeams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strength (B) and line charge density is such that (Ba)2

This chapter gives an introduction to low-energy beam transport systems, and discusses the typically used magnetostatic elements (solenoid, dipoles and quadrupoles) and electrostatic elements (einzel lens, dipoles and quadrupoles). The ionbeam emittance, beam space-charge effects and the physics of ion source extraction are introduced. Typical computer codes for analysing and designing ion optical systems are mentioned, and the trajectory tracking method most often used for extraction simulations is described in more detail.

A new 3 dimensional ray tracing code BEAM-3D, with a simple model to calculate the space charge force of multiple ion species, is under development and serves as a theoretical tool to study the ECRIS beam formation. Excellent agreement between the BEAM-3D calculations and beam profile and emittance measurements of the total extracted helium 1+ beam from the RTECR ion source was obtained when a low degree of beam neutralization was assumed in the calculations. The experimental evidence indicates that the positive space charge effects dominate the early RTECR ion source beam formation and beamline optics matching process. A review of important beam characteristics is made, including a conceptual model for the space charge beam blow up. Better beam transport through the RTECR beamline analysis magnet has resulted after an extraction geometry modification in which the space charge force was more correctly matched. This work involved the development of an online beam characteristic measuring apparatus which will also be described

Ionbeam formation at low energy (∼1 keV or so) is more difficult to accomplish than at high energy because of beam blowup by space-charge forces in the uncompensated region within the extractor, an effect which is yet more pronounced for heavy ions and for high beam current density. For the same reasons, the extractedionbeam is more strongly subject to space charge blowup than higher energy beams if it is not space-charge neutralized to a high degree. A version of vacuum arc ion source with an extractor that produces low-energy metal ionbeams at relatively high current (∼0.5--10 kV at up to ∼100 mA) using a multi-aperture, accel--decel extractor configuration has been created. The experimentally observed beamextraction characteristics of this source is compared with those predicted using the AXCEL-INP code, and the implied downstream beam transport with theoretical expectations. It is concluded that the low-energy extractor performance is in reasonable agreement with the code, and that good downstream space charge neutralization is obtained. Here, the code and the experimental results are described, and the features that contribute to good low-energy performance are discussed

The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ionbeams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beamextraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ionbeams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extractedbeams and a way to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work.

An ionbeam analyzer is specified, having an ion source for generating ions of a sample to be analyzed, means for extracting the sample ions, means for focusing the sample ions into a beam, separation means positioned along the ionbeam for selectively deflecting species of ions, and means for detecting the selected species of ions. According to the specification, the analyzer further comprises (a) means for disabling at least a portion of the separation means, such that the ionbeam from the source remains undeflected; (b) means located along the path of the undeflected ionbeam for sensing the sample ions; and (c) enabling means responsive to the sensing means for automatically re-enabling the separation means when the sample ions reach a predetermined intensity level. (author)

In order to extend the life of anodes of pulsed ion diodes, a trial was made to extractions from a plasma created by surface flashover on the oil-covered anode. The diode with this anode worked well as a so-called pinched electron beam diode. Production of proton beams of 10 kA with energies of about 400 keV was confirmed by measurements with biased ion collectors and those of prompt γ-rays from the reaction 19 F(p,γα) 16 O. Substantial reduction of damage and substantial extension of the life of the anode disc were realized. (author)

Since an ionbeam is hoped to impinge on a target in a spherically symmetric way for inertial confinement fusion, an analysis is developed here for the intense ionbeam which is extracted from a spherical reflex triode. The basic equations are the Poisson equation for the electric potential and the conservation equations of energies for the ion and electron velocities. According to the asymptotic solution, the extractedion-beam-current density is proportional to the power of 3/2 of the voltage imposed on the triode. This dependence of the current density on the voltage is improved to be the power of 1.6 by the numerical analysis. A special time-dependence of the ion-beam power at the target surface is required for an optimal implosion of the target. Using the bunching theory for the ionbeam, we derive numerically an optimal time-dependence of the voltage imposed on the triode. Asymptotic forms are also obtained analytically for the voltage. (author)

ROBIN, the first step in the Indian R&D program on negative ionbeams has reached an important milestone, with the production of negative ions in the surface conversion mode through Cesium (Cs) vapor injection into the source. In the present set-up, negative hydrogen ionbeamextraction is effected through an extraction area of ˜73.38 cm2 (146 apertures of 8mm diameter). The three grid electrostatic accelerator system of ROBIN is fed by high voltage DC power supplies (Extraction Power Supply System: 11kV, 35A and Acceleration Power Supply System: 35kV, 15A). Though, a considerable reduction of co-extracted electron current is usually observed during surface mode operation, in order to increase the negative ion current, various other parameters such as plasma grid temperature, plasma grid bias, extraction to acceleration voltage ratio, impurity control and Cs recycling need to be optimized. In the present experiments, to control and to understand the impurity behavior, a Cryopump (14,000 l/s for Hydrogen) is installed along with a Residual Gas Analyzer (RGA). To characterize the source plasma, two sets of Langmuir probes are inserted through the diagnostic flange ports available at the extraction plane. To characterize the beam properties, thermal differential calorimeter, Doppler Shift Spectroscopy and electrical current measurements are implemented in ROBIN. In the present set up, all the negative ionbeamextraction experiments have been performed by varying different experimental parameters e.g. RF power (30-70 kW), source operational pressure (0.3 - 0.6Pa), plasma grid bias voltage, extraction & acceleration voltage combination etc. The experiments in surface mode operation is resulted a reduction of co-extracted electron current having electron to ion ratio (e/i) ˜2 whereas the extracted negative ion current density was increased. However, further increase in negative ion current density is expected to be improved after a systematic optimization of the

In order to improve the quality of ionbeamsextracted from ECR ion sources it is mandatory to better understand the relations between the plasma conditions and the beam properties. The present investigations concentrate on the analysis of different beam properties under the influence of various applications of frequency tuning and of multiple frequency heating. The changes in the microwave frequency feeding the plasma affect the electromagnetic field distribution and the dimension and position of the ECR surface inside the plasma chamber. This in turn has an influence on the generation of the extractedionbeam in terms of intensity, shape and emittance. In order to analyze the corresponding effects, measurements have been performed with the CAPRICE-Type ECRIS installed at the ECR Injector Setup (EIS) of GSI. The experimental setup uses a microwave sweep generator which feeds a TWTA (Traveling Wave Tube Amplifier) covering a wide frequency range from 12.5 to 16.5 GHz. This arrangement provides a precise determination of the frequencies and of the reflection coefficient along with the beam properties and it confirms again how the frequency and the corresponding electromagnetic field feeding the plasma affects the ECRIS performances. A sequence of viewing targets positioned inside the beam line monitors the beam shape evolution. The paper is followed by the associated poster

ROBIN (Replica Of BATMAN source in India) is a replica of BATMAN source of IPP, Garching. Plasma production (inductively coupled, RF produced plasma), plasma diagnostic (langmuir probe, optical emission spectroscopy), negative ionbeamextraction in volume mode with reduced extraction area of 2 cm 2 (4 apertures) using small bench top type power supply (10kV, 400mA), with increase extraction area of 73 cm 2 (146 apertures) and using actual power supplies (Extraction Power Supply System, EPSS (11kV, 35A), and Accelerator Power Supply System, APSS (35kV, 15A)) and beam diagnostic etc have been performed successfully in ROBIN. This paper will describe the details of the system upgradation for surface mode negative ion experiments and its performance in ROBIN

In this study we first model a DC low pressure wire plasma source and then characterize the properties of an ion gun derived from the plasma source. In order to study the properties of the derived ion gun, we develop a particle-in-cell code fitted to the modelling of the wire plasma source operation, and validate it by confrontation with the results of an experimental study. In light of the simulation results, an analysis of the wire discharge in terms of a collisional Child-Langmuir ion flow in cylindrical geometry is proposed. We interpret the mode transition as a natural reorganization of the discharge when the current is increased above a threshold value which is a function of the discharge voltage, the pressure and the inter-electrodes distance. In addition, the analysis of the energy distribution function of ions impacting the cathode demonstrates the ability to extract an ionbeam of low energy spread around the discharge voltage assuming that the discharge is operated in its high pressure mode. An ion source prototype allowing the extraction and acceleration of ions from the wire source is then proposed. The experimental study of such a device confirms that, apart from a shift corresponding to the accelerating voltage, the acceleration scheme does not spread the ion velocity distribution function along the axis of the beam. It is therefore possible to produce tunable energy (0 - 5 keV) ionbeams of various ionic species presenting limited energy dispersion (∼ 10 eV). The typical beam currents are about a few tens of micro-amperes, and the divergence of such a beam is on the order of one degree. A numerical modelling of the ion source is eventually conducted in order to identify potential optimizations of the concept. (author)

The development of the Linac 4 and its integration into CERN’s acceleration complex is part of the foreseen luminosity upgrade of the Large Hadron Collider (LHC). The goal is to inject a 160 MeV H{sup −} beam into the CERN PS Booster (PSB) in order to increase the beam brightness by a factor of 2 compared to the 50 MeV proton linac, Linac 2, that is currently in operation. The requirements for the ion source are a 45 keV H{sup −} beam of 80 mA intensity, 2 Hz repetition rate and 0.5 ms pulse length within a normalized rms-emittance of 0.25 mm· mrad. The previously installed beamextraction system has been designed for an H{sup −} ionbeam intensity of 20 mA produced by an RF-volume source with an electron to H{sup −} ratio of up to 50. For the required intensity upgrades of the Linac4 ion source, a new beamextraction system is being produced and tested; it is optimized for a cesiated surface RF-source with a nominal beam current of 40 mA and an electron to H{sup −} ratio of 4. The simulations, based on the IBSIMU code, are presented. At the Brookhaven National Laboratory (BNL), a peak beam current of more than 100 mA was demonstrated with a magnetron H{sup −} source at an energy of 35 keV and a repetition rate of 2 Hz. A new extraction system is required to operate at an energy of 45 keV; simulation of a two stage extraction system dedicated to the magnetron is presented.

Methods and apparatus for producing intense megavolt ionbeams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation

Nitride-based thin-film materials have become increasingly important for the high brightness light-emitting diode applications. The improvements in light extraction and lower power consumption are highly desired. Although the internal quantum efficiency of GaN-based LED has been relatively high, only a small fraction of light can be extracted. In this study, a new design of two-dimensional photonic crystal array has been prepared on the top transparent contact layer of indium-tin oxide film to improve the light extraction efficiency using focused ionbeam. The acceleration voltage of the Ga dual-beam nanotechnology system SMI 3050 was 30 kV and the ionbeam current was 100 pA. The cylindrical air holes had the diameter of 150 nm and depth of 100 nm. The micro photoluminescence analysis results showed that the light output intensity could be 1.5 times of that of the non-patterned control sample. In addition, the structural damage from the focused ionbeam drilling of GaN step could be eliminated. The excellent I-V characteristics have been maintained, and the external light extraction efficiency would be still improved for the LED devices. (author)

Electron beamion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ionbeam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ionbeams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

Highly charged ions are extracted from the Berlin Electron BeamIon Trap for investigations of charge exchange with a gas target. The classical over-the-barrier model for slow highly charged ions describes this process, whereby one or more electrons are captured from the target into Rydberg states of the ion. The excited state relaxes via a radiative cascade of the electron to ground energy. The cascade spectra are characteristic of the capture state. We investigate x-ray photons emitted as a result of interactions between Ar 17+ ions at energies ≤5q keV with Ar atoms. Of particular interest is the velocity dependence of the angular momentum capture state l c

The development of a large area (Asource,ITER = 0.9 × 2 m2) hydrogen negative ion (NI) source constitutes a crucial step in construction of the neutral beam injectors of the international fusion reactor ITER. To understand the plasma behaviour in the boundary layer close to the extraction system the 3D PIC MCC code ONIX is exploited. Direct cross checked analysis of the simulation and experimental results from the ITER-relevant BATMAN source testbed with a smaller area (Asource,BATMAN ≈ 0.32 × 0.59 m2) has been conducted for a low perveance beam, but for a full set of plasma parameters available. ONIX has been partially benchmarked by comparison to the results obtained using the commercial particle tracing code for positive ionextraction KOBRA3D. Very good agreement has been found in terms of meniscus position and its shape for simulations of different plasma densities. The influence of the initial plasma composition on the final meniscus structure was then investigated for NIs. As expected from the Child-Langmuir law, the results show that not only does the extraction potential play a crucial role on the meniscus formation, but also the initial plasma density and its electronegativity. For the given parameters, the calculated meniscus locates a few mm downstream of the plasma grid aperture provoking a direct NI extraction. Most of the surface produced NIs do not reach the plasma bulk, but move directly towards the extraction grid guided by the extraction field. Even for artificially increased electronegativity of the bulk plasma the extracted NI current from this region is low. This observation indicates a high relevance of the direct NI extraction. These calculations show that the extracted NI current from the bulk region is low even if a complete ion-ion plasma is assumed, meaning that direct extraction from surface produced ions should be present in order to obtain sufficiently high extracted NI current density. The calculated extracted currents, both ions

The development of a large area (A source,ITER = 0.9 × 2 m 2 ) hydrogen negative ion (NI) source constitutes a crucial step in construction of the neutral beam injectors of the international fusion reactor ITER. To understand the plasma behaviour in the boundary layer close to the extraction system the 3D PIC MCC code ONIX is exploited. Direct cross checked analysis of the simulation and experimental results from the ITER-relevant BATMAN source testbed with a smaller area (A source,BATMAN ≈ 0.32 × 0.59 m 2 ) has been conducted for a low perveance beam, but for a full set of plasma parameters available. ONIX has been partially benchmarked by comparison to the results obtained using the commercial particle tracing code for positive ionextraction KOBRA3D. Very good agreement has been found in terms of meniscus position and its shape for simulations of different plasma densities. The influence of the initial plasma composition on the final meniscus structure was then investigated for NIs. As expected from the Child–Langmuir law, the results show that not only does the extraction potential play a crucial role on the meniscus formation, but also the initial plasma density and its electronegativity. For the given parameters, the calculated meniscus locates a few mm downstream of the plasma grid aperture provoking a direct NI extraction. Most of the surface produced NIs do not reach the plasma bulk, but move directly towards the extraction grid guided by the extraction field. Even for artificially increased electronegativity of the bulk plasma the extracted NI current from this region is low. This observation indicates a high relevance of the direct NI extraction. These calculations show that the extracted NI current from the bulk region is low even if a complete ion–ion plasma is assumed, meaning that direct extraction from surface produced ions should be present in order to obtain sufficiently high extracted NI current density. The calculated

Highlights: • A high-current ion source is developed for NBI system of VEST. • A cold-cathode electron gun is employed to produce primary electrons. • A hemi-cylindrical discharge chamber with cusp magnetic field is used. • Plasma density is measured to be 2 × 10{sup 18} m{sup −3} near the extraction aperture. • NBI power of 90 kW with beam energy of 20 keV is expected to be achieved. - Abstract: A high-current pulsed ion source has been developed for the neutral beam injector of the VEST (Versatile Experiment Spherical Torus) to accommodate high-beta fusion plasma experiments. The ion source consists of two parts: an electron gun for supplying sufficient primary electrons by cold-cathode arc discharge and a hemi-cylindrical discharge chamber where uniform, high-density plasma generated by the primary electrons is confined by multi-cusp magnetic field. A pulse forming network is also developed to drive high current of ∼1 kA to sustain the cold-cathode discharge in the electron gun up to 10 ms. Diagnostics with a triple probe in the discharge chamber shows that a hydrogen plasma whose density is as high as 1 × 10{sup 18} m{sup −3} can be obtained near extraction slits at the gas pressure lower than 0.5 Pa. This value is estimated to be sufficient to deposit a heating power of 90 kW to the VEST plasma when the appropriate extraction through slits with 20 cm{sup 2} in area and acceleration of ionbeams up to 20 kV are fulfilled.

Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ionbeams for the CERN experimental program. The ionbeams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ionbeam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented.

This thesis concerns the beamextraction studies of ECR Ion Sources for the SPIRAL project at GANIL (France). The optical properties (i.e. the emittances) of the radioactive ionbeam production source is a crucial point in this project. We performed emittance measurements with a very high transport efficiency and developed a computer code for simulating the extraction and transport conditions. This simulation takes into account all the parameters acting on the extraction process: the characteristics of the ions and electrons emitted by the plasma, their space and energy distributions, the space charge, the magnetic filed of the source and the accelerating electric field. We explained the evolution of the emittances for two different types of ECR Ion Source. The simulation-experiment comparison showed us that the magnetic field and the intrinsic energy of the ions seem to be the most important parameters for explaining the overall emittance behaviour of the ECRIS. We precise their values and comment them. (author)

In the scope of an upgrade of the injector chain of CERN’s accelerator complex, a new linear accelerator, Linac4, is under construction. This accelerator will replace the existing 50 MeV proton linac, Linac2. By increasing the beam energy to 160 MeV, Linac4 makes it possible to double the brightness in the PSB, and ultimately increase the luminosity in the LHC. Linac4 will accelerate beams of negative hydrogen (H-) to be injected into the PSB by multi-turn, charge exchange injection. The ion source was initially based on the non-caesiated RF-volume source from DESY. However, the beamextraction from this source could not handle the 45 keV beam energy required by the RFQ. A new beamextraction system has therefore been designed, via IBSimu simulations [1], to extract and transport the H- ionbeam respecting the Linac4 requirements. Key features of the extraction system is a tuneable puller voltage to adapt the extraction field to the ion and electron beam currents, and a magnetized Einzel lens to dump the co...

“Photonic Crystals (PhC)” have been used in a variety of fields as a structure for improving the light extraction efficiency from materials with high index of refraction. In previous work we already showed the light extraction improvement of several PhC covered LYSO crystals in computer simulations and practical measurements. In this work, new samples are made using different materials and techniques which allows further efficiency improvements. For rapid prototyping of PhC patterns on scintillators we tested a new method using “Focused IonBeam (FIB)” patterning. The FIB machine is a device similar to a “Scanning Electron Microscope (SEM)”, but it uses ions (mainly gallium) instead of electrons for the imaging of the samples' surface. The additional feature of FIB devices is the option of surface patterning in nano-scale which was exploited for our samples. Three samples using FIB patterning have been produced. One of them is a direct patterning of the extraction face of a 0.8×0.8×10 $mm^3$ LYS...

An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beamextraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beamextraction and it works well to improve the extractedbeam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

We model the extraction of negative ions from a high brightness high power magnetized negative ion source. The model is a Particle-In-Cell (PIC) algorithm with Monte-Carlo Collisions. The negative ions are generated only on the plasma grid surface (which separates the plasma from the electrostatic accelerator downstream). The scope of this work is to derive scaling laws for the negative ionbeam properties versus the extraction voltage (potential of the first grid of the accelerator) and plasma density and investigate the origins of aberrations on the ionbeam. We show that a given value of the negative ionbeam perveance correlates rather well with the beam profile on the extraction grid independent of the simulated plasma density. Furthermore, the extractedbeam current may be scaled to any value of the plasma density. The scaling factor must be derived numerically but the overall gain of computational cost compared to performing a PIC simulation at the real plasma density is significant. Aberrations appear for a meniscus curvature radius of the order of the radius of the grid aperture. These aberrations cannot be cancelled out by switching to a chamfered grid aperture (as in the case of positive ions).

The fundamental and practical aspects are described for extractingions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T e ) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n e ) is in the range 10 8 --10 10 -cm at the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 near the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ionbeam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10 4 --10 5 downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z 2 intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z 2 fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument

The fraction of metastable-state Ar 2 + (3p 4 1 D) ions in Ar 2 + beam has been determined by an optical attenuation method (OAM) combined with the conventional beam attenuation method. The present OAM is based on observation of spatial decay of specified emission line intensities arising from charge-changed ions, along the beam axis in a target gas cell. The validity of the OAM is discussed in detail. The cross sections for one-electron capture by the ground-state Ar 2 + ( 3 P) ions, σ 21 , and by the metastable-state Ar 2 + ( 1 D) ions, σ 21 *, from Na have been measured independently by the OAM. Both the cross sections are of the order of 10 - 14 cm 2 and σ 21 * is about 1.3 times as large as σ 21 at the collision energy of 1.5 keV. (author)

A portable test bench is described, which was designed to check ion sources, ionbeamextraction and focusing systems before its use in a 600 KeV Cockcroft-Walton accelerator. The vacuum possibilities of the system are specially analyzed in connection with its particular use. The whole can be considered as a portable accelerator of low energy (50 keV). (Author)

Prototype long pulse ion sources are being developed and tested toward the goal of a deuterium beamextraction of 120 keV/65 A. The latest prototype source consists of a magnetic bucket plasma generator and a four-grid copper accelerator system with multicircular apertures of 568 holes. To measure the angular divergence and the ion species of the ionbeam, an optical multichannel analyzer (OMA) system for a Doppler-shifted H-alpha lights was set up at the end of a gas-cell neutralizer. But the OMA data are very difficult to analyze due to a large background level on the top of the three energy peaks (coming from H + , H 2 + , and H 3 + ). These background spectra in the OMA signals seem to result from partially accelerated ionbeams in the accelerator. Extractedions could undergo a premature charge exchange as the accelerator column tends to have a high hydrogen partial pressure from the unused gas from the plasma generator, resulting in a continuous background of partially accelerated beam particles at the accelerator exit. This effect is calculated by accounting for all the possible atomic collision processes and numerically summing up three ion species across the accelerator column. The collection of all the atomic reaction cross sections and the numerical summing up will be presented. The result considerably depends on the background pressure and the ionbeam species ratio (H + , H 2 + , and H 3 + ). This effect constitutes more than 20% of the whole particle distribution. And the energy distribution of those suffering from collisions is broad and shows a broad maximum in the vicinity of the half and the third energy region

The development of a high performance negative ion (NI) source constitutes a crucial step in the construction of a Neutral Beam Injector of the future fusion reactor ITER. NI source should deliver 40 A of H - or of D - . To address this problem in a realistic way, a 3D particles-in-cell electrostatic collisional code was developed. Binary collisions between the particles are introduced using Monte-Carlo collision scheme. This code called ONIX was used to investigate the plasma properties and the transport of the charged particles close to a typical extraction aperture. Results obtained from this code are presented in this thesis. They include negative ions and electrons 3D trajectories. The ion and electron current density profiles are shown for different local magnetic field configurations. Results of production, destruction, and transport of H - in the extraction region are also presented. The production of H - is investigated via 3 atomic processes: 1) electron dissociative attachment to the vibrationally excited molecules H 2 (v) in the volume, 2) interaction of the positive ions H + and H 2 + with the aperture wall and 3) collisions of the neutral gas H, H 2 with aperture wall. The influence of each process on the total extracted NI current is discussed. The extraction efficiency of H - from the volume is compared to the one of H - coming from the wall. Moreover, a parametric study of the H - surface production is presented. Results show the role of sheath behavior in the vicinity of the aperture developing a double layer structure responsible of the NI extraction limitations. The 2 following issues are also analysed. First the influence of the external extracted potential value on the formation of negative sheath and secondly the strength of the magnetic filter on the total extracted NI and co-extracted electron current. The suppression of the electron beam by the negative ion produced at the plasma grid wall is also discussed. Results are in good agreement

The IonBeam Propulsion Study was a joint high-level study between the Applied Physics Laboratory operated by NASA and ASRC Aerospace at Kennedy Space Center, Florida, and Berkeley Scientific, Berkeley, California. The results were promising and suggested that work should continue if future funding becomes available. The application of ion thrusters for spacecraft propulsion is limited to quite modest ion sources with similarly modest ionbeam parameters because of the mass penalty associated with the ion source and its power supply system. Also, the ion source technology has not been able to provide very high-power ionbeams. Small ionbeam propulsion systems were used with considerable success. Ion propulsion systems brought into practice use an onboard ion source to form an energetic ionbeam, typically Xe+ ions, as the propellant. Such systems were used for steering and correction of telecommunication satellites and as the main thruster for the Deep Space 1 demonstration mission. In recent years, "giant" ion sources were developed for the controlled-fusion research effort worldwide, with beam parameters many orders of magnitude greater than the tiny ones of conventional space thruster application. The advent of such huge ionbeam sources and the need for advanced propulsion systems for exploration of the solar system suggest a fresh look at ionbeam propulsion, now with the giant fusion sources in mind.

This report is an introduction to ionbeam diagnosis. After a short description of the most important ionbeam parameters measurements of the beam current by means of Faraday cups, calorimetry, and beam current transformers and measurements of the beam profile by means of viewing screens, profile grids and scanning devices, and residual gas ionization monitors are described. Finally measurements in the transverse and longitudinal phase space are considered. (HSI)

The upgraded millimeter-wave interferometer with the frequency of 70 GHz is installed on a large-scaled negative ion source. Measurable line-averaged electron density is from 2 × 10{sup 15} to 3 × 10{sup 18} m{sup −3} in front of the plasma grid. Several improvements such as the change to shorter wavelength probing with low noise, the installation of special ordered horn antenna, the signal modulation for a high accuracy digital phase detection, the insertion of insulator, and so on, are carried out for the measurement during the beamextraction by applying high voltage. The line-averaged electron density is successfully measured and it is found that it increases linearly with the arc power and drops suddenly at the beamextraction.

Ionbeam techniques, including conventional broad beamion implantation, ionbeam synthesis and ion irradiation of thin layers, as well as local ion implantation with fine-focused ionbeams have been applied in different fields of micro- and nanotechnology. The ionbeam synthesis of nanoparticles in high-dose ion-implanted solids is explained as phase separation of nanostructures from a super-saturated solid state through precipitation and Ostwald ripening during subsequent thermal treatment of the ion-implanted samples. A special topic will be addressed to self-organization processes of nanoparticles during ion irradiation of flat and curved solid-state interfaces. As an example of silicon nanocrystal application, the fabrication of silicon nanocrystal non-volatile memories will be described. Finally, the fabrication possibilities of nanostructures, such as nanowires and chains of nanoparticles (e.g. CoSi2), by ionbeam synthesis using a focused Co+ ionbeam will be demonstrated and possible applications will be mentioned.

Several fluorescent materials were tested for use in the imaging screen of a pepper-pot emittance meter that is suitable for investigating the beam dynamics of multiply charged heavy ionsextracted from an ECR ion source. SiO{sub 2} (quartz), KBr, Eu-doped CaF{sub 2}, and Tl-doped CsI crystals were first irradiated with 6.52-keV protons to determine the effects of radiation damage on their fluorescence emission properties. For such a low-energy proton beam, only the quartz was found to be a suitable fluorescent material, since the other materials suffered a decay in fluorescence intensity with irradiation time. Subsequently, quartz was irradiated with heavy {sup 12}C{sup 4+}, {sup 16}O{sup 4+}, and {sup 40}Ar{sup 11+} ions, but it was found that the fluorescence intensity decreased too rapidly to measure the emittance of these heavy-ionbeams. These results suggest that a different energy loss mechanism occurs for heavier ions and for protons.

In this work the effect of gas mixing on the production efficiency of ionbeamsextracted from an ECR ion source has been studied with the JYFL 6.4 GHz electron cyclotron resonance ion source (ECRIS). It was found that the gas mixing affects strongly the confinement of ions in the plasma of the ECRIS. The information obtained can be used to minimize the consumption of expensive materials or isotopes and to reduce contamination of the plasma chamber. It was observed that the carbon contamination, which is built up when the MIVOC method is used could be decreased with the aid of the gas mixing technique. The best mixing gas for this purpose was found to be oxygen

Here we present results of the further development of two novel ideas in the field of slow RI-beams production. They are a fair-wind gas cell concept for big-size high-pressure buffer gas cells and a new approach to the extraction system. For this purpose, detailed gas dynamic simulations based on the solution of a full system of time-dependent Navier-Stokes equations have been performed for both the fair-wind gas cell of 500 mm length at 1 bar helium buffer gas pressure and the RF-funnel extraction system at low buffer gas pressure. The results of gas dynamic calculations were used for detailed microscopic Monte Carlo ion-beam trajectory simulations under the combined effect of the buffer gas flow and electric fields of the RF-funnels. The obtained results made it apparent that the use of the fair-wind gas cell concept and extraction RF-funnels look very promising for production of high-quality low-energy RI-beams

A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ionbeams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

Operational commissioning of ROBIN forms an important milestone in the Indian programme on the R&D on negative ionbeams. The commissioning activity has been effected in sequence, in synchronisation with the availability of High voltage Power Supply (HVPS) systems and routine operation has now been established in the cesiated, surface mode. Significant efforts have been placed in upgrading the system to initiate the surface mode operation. These include incorporation of a temperature controlled Cesium (Cs) delivery system, spectroscopic diagnostics for detection of Cs lines, installation of plasma grid heating and closed loop warm water circuit for source components heating and Doppler Shift Spectroscopy (DSS) system. The specific design and integration features for these upgrades are discussed and preliminary results obtained from the operation of ROBIN in the surface mode are presented.

Operational commissioning of ROBIN forms an important milestone in the Indian programme on the R&D on negative ionbeams. The commissioning activity has been effected in sequence, in synchronisation with the availability of High voltage Power Supply (HVPS) systems and routine operation has now been established in the cesiated, surface mode. Significant efforts have been placed in upgrading the system to initiate the surface mode operation. These include incorporation of a temperature controlled Cesium (Cs) delivery system, spectroscopic diagnostics for detection of Cs lines, installation of plasma grid heating and closed loop warm water circuit for source components heating and Doppler Shift Spectroscopy (DSS) system. The specific design and integration features for these upgrades are discussed and preliminary results obtained from the operation of ROBIN in the surface mode are presented.

In the past a number of ionbeam sources utilizing different methods for plasma excitation have been developed. Nevertheless, a widespread use in industrial applications has not happened, since the sources were often not able to fulfill specific demands like: broad homogeneous ionbeams, compatibility with reactive gases, low ion energies at high ion current densities or electrical neutrality of the beam. Our contribution wants to demonstrate technical capabilities of rf ion and plasma beam sources, which can overcome the above mentioned disadvantages. The physical principles and features of respective sources are presented. We report on effective low pressure plasma excitation by electron cyclotron wave resonance (ECWR) for the generation of dense homogeneous plasmas and the rf plasma beamextraction method for the generation of broad low energy plasma beams. Some applications like direct plasma beam deposition of a-C:H and ionbeam assisted deposition of Al and Cu with tailored thin film properties are discussed. (orig.).

In the past a number of ionbeam sources utilizing different methods for plasma excitation have been developed. Nevertheless, a widespread use in industrial applications has not happened, since the sources were often not able to fulfill specific demands like: broad homogeneous ionbeams, compatibility with reactive gases, low ion energies at high ion current densities or electrical neutrality of the beam. Our contribution wants to demonstrate technical capabilities of rf ion and plasma beam sources, which can overcome the above mentioned disadvantages. The physical principles and features of respective sources are presented. We report on effective low pressure plasma excitation by electron cyclotron wave resonance (ECWR) for the generation of dense homogeneous plasmas and the rf plasma beamextraction method for the generation of broad low energy plasma beams. Some applications like direct plasma beam deposition of a-C:H and ionbeam assisted deposition of Al and Cu with tailored thin film properties are discussed. (orig.)

In this work the emittance measurements of high current Ta-beam provided by VARIS (Vacuum Arc Ion Source) ion source are presented. Beam brilliance as a function of beam aperture at various extraction conditions is investigated. Influence of electrostatic ionbeam compression in post acceleration gap on the beam quality is discussed. Use of different extraction systems (single aperture, 7 holes, and 13 holes) in order to achieve more peaked beam core is considered. The possible ways to increase the beam brilliance are discussed.

A description of techniques for the production of intense beams of heavy ions is given. A table of recommended operational procedures for most elements is included. The ionisation of boron is considered in some detail because of its particular importance as a dopant for ion implantation. (author)

Ionbeam technology is one of best ways for the modification of biomaterials. The results of ionbeam modification of biomaterials are given. The method and results of improved biocompatibility are indicated by ionbeam technology. The future development of ionbeam modification of biomaterials is discussed

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm2 have been measured from lithium alumino-silicate ion sources at a temperature of ~1275 °C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm2, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, ≤0.25 mm thick, has a measured lifetime of ~40 h at ~1275 °C, when pulsed at 0.05 Hz and with pulse length of ~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Finally, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm2 have been measured from lithium alumino-silicate ion sources at a temperature of ~1275 °C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm2, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, ≤0.25 mm thick, has a measured lifetime of ~40 h at ~1275 °C, when pulsed at 0.05 Hz and with pulse length of ~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Finally, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beamextraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ionbeam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ionbeam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface

The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beamextraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ionbeam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ionbeam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

Los Alamos Scientific Laboratory fiscal year 1975 work on production of intense, very bright, negative hydrogen (H - ), ionbeams and conversion of a high-energy (a few hundred MeV) negative beam into a neutral beam are described. The ion source work has used a cesium charge exchange source that has produced H - ionbeams greater than or equal to 10 mA (about a factor of 10 greater than those available 1 yr ago) with a brightness of 1.4 x 10 9 A/m 2 -rad 2 (about 18 times brighter than before). The high-energy, neutral beam production investigations have included measurements of the 800-MeV H - -stripping cross section in hydrogen gas (sigma/sub -10/, tentatively 4 x 10 -19 cm 2 ), 3- to 6-MeV H - -stripping cross sections in a hydrogen plasma (sigma/sub -10/, tentatively 2 to 4 x 10 -16 cm 2 ), and the small-angle scattering that results from stripping an 800-MeV H - ionbeam to a neutral (H 0 ) beam in hydrogen gas. These last measurements were interrupted by the Los Alamos Meson Physics Facility shutdown in December 1974, but should be completed early in fiscal year 1976 when the accelerator resumes operation. Small-angle scattering calculations have included hydrogen gas-stripping, plasma-stripping, and photodetachment. Calculations indicate that the root mean square angular spread of a 390-MeV negative triton (T - ) beam stripped in a plasma stripper may be as low as 0.7 μrad

A microscopic surface texture was created by sputter-etching a surface while simultaneously sputter-depositing a lower sputter yield material onto the surface. A xenon ion-beam source was used to perform the texturing process on samples as large as 3-cm diameter. Textured surfaces have been characterized with SEM photomicrographs for a large number of materials including Cu, Al, Si, Ti, Ni, Fe, stainless steel, Au, and Ag. A number of texturing parameters are studied including the variation of texture with ion-beam powder, surface temperature, and the rate of texture growth with sputter etching time.

About twenty years ago, A. W. Maschke of Brookhaven National Laboratory and R. L. Martin of Argonne National Laboratory recognized that the accelerators that have been developed for high energy and nuclear physics are, in many ways, ideally suited to the requirements of inertial fusion power production. These accelerators are reliable, they have a long operating life, and they can be efficient. Maschke and Martin noted that they can focus ionbeams to small focal spots over distances of many meters and that they can readily operate at the high pulse repetition rates needed for commercial power production. Fusion, however, does impose some important new constraints that are not important for high energy or nuclear physics applications. The most challenging new constraint from a scientific standpoint is the requirement that the accelerator deliver more than 10 14 W of beam power to a small quantity (less than 100 mg) of matter. The most challenging constraint from an engineering standpoint is accelerator cost. Maschke showed theoretically that accelerators could produce adequate work. Heavy-ion fusion is widely recognized to be a promising approach to inertial fusion power production. It provides an excellent opportunity to apply methods and technology developed for basic science to an important societal need. The pulsed-power community has developed a complementary, parallel approach to ionbeam fusion known as light-ion fusion. The talk will discuss both heavy-ion and light-ion fusion. It will explain target physics requirements and show how they lead to constraints on the usual accelerator parameters such as kinetic energy, current, and emittance. The talk will discuss experiments that are presently underway, specifically experiments on high-current ion sources and injectors, pulsed-power machines recirculating induction accelerators, and transverse beam combining. The talk will give a brief description of a proposed new accelerator called Elise

The storage ring ESR has been used in various operational modes for experiments with electron cooled heavy ionbeams. Besides the standard storage mode including injection and beam accumulation the deceleration of highly charged ions has been demonstrated. Beams of highly charged ions have been injected and accumulated and finally decelerated to a minimum energy of 50 MeV/u. An ultraslow extraction method using charge changing processes is now also available for cooled beams of highly charged ions. For in ring experiments the internal gas jet and the cold electron beam of the cooling system are applied as targets. High precision mass spectrometry by Schottky noise detection has been demonstrated. Operation at transition energy has been achieved with cooled beams opening the field for experiments which require an isochronous revolution of the ions. (orig.)

The paper reports about performance tests of newly designed Secondary Electron Monitors (SEM), Ionization Chambers (IC) and Multi Diode Counters (MDC). Especially the linearity of the detectors with respect to the specific energy loss will be discussed. Calibration has been performed by means of scintillation particle counters at the lower end of the intensity region. The status of the Cryogenic Current Comparator (CCC), which is provided for absolute measurements and calibration of detectors above some nA of beam current is reported, too. (orig.)

Full text: Ionbeam analysis is an accelerator application area for the study of materials and the structure of matter; electrostatic accelerators of the Van de Graaff or Dynamitron type are often used for energies up to a few MeV. Two types of machines are available - the single-ended accelerator type with higher beam currents and greater flexibility of beam management, or the tandem accelerator, limited to atomic species with negative ions. The accelerators are not generally installed at specialist accelerator laboratories and have to be easy to maintain and simple to operate. The most common technique for industrial research is Rutherford Back Scattering Spectrometry (RBS). Helium ions are the preferred projectiles, since at elevated energies (above 3 MeV) nuclear resonance scattering can be used to detect photons associated with target molecules containing elements such as carbon, nitrogen or oxygen. Due to the large amount of available data on nuclear reactions in this energy range, activation analysis (detecting trace elements by irradiating the sample) can be performed with charged particles from accelerators over a wider range of atoms than with the conventional use of neutrons, which is more suited to light elements. Resonance reactions have been used to detect trace metals such as aluminium, titanium and vanadium. Hydrogen atoms are vital to the material performance of several classes of materials, such as semiconductors, insulators and ceramics. Prudent selection of the projectile ion aids the analysis of hydrogen composition; the technique is then a simple measurement of the emitted gamma radiation. Solar cell material and glass can be analysed in this way. On a world-wide basis, numerous laboratories perform ionbeam analysis for research purposes; considerable work is carried out in cooperation between scientific laboratories and industry, but only a few laboratories provide a completely commercial service

Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ionbeam lithography machine, which will be used for the projection of sub-0.2 {mu}m patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma.

Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ionbeam lithography machine, which will be used for the projection of sub-0.2 μm patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma

Theoretical and experimental analyses and their comparison were made on the plasma generation and on the beamextraction for the beam plasma ion-source. The operational principle and the structure of the ion-source are explained in the first part. Considerations are given on the electron beam-plasma interaction and the resulting generation of high frequency or microwaves which in turn increases the plasma density. The flow of energy in this system is also explained in the second part. The relation between plasma density and the imaginary part of frequency is given by taking the magnetic flux density, the electron beam energy, and the electron beam current as parameters. The relations between the potential difference between collector and drift tube and the plasma density or the ion-current are also given. Considerations are also given to the change of the plasma density due to the change of the magnetic flux density at drift tube, the change of the electron beam energy, and the change of the electron beam current. The third part deals with the extraction characteristics of the ionbeam. The structure of the multiple-aperture electrode and the relation between plasma density and the extractedion current are explained. (Aoki, K.)

The testing equipment was designed, manufactured and tried out permitting measurements of total current, current profile and emittance of an ionbeamextracted from the ionbeam. MeV energy electrostatic accelerator ion H + beam emittance measurement results are presented.

Focussed ionbeam (FIB) technology has the advantage of being a maskless process compatible with UHV processing. This makes it attractive for use in in situ processing and has been applied to the fabrication of various mesoscopic structures. The present paper reviews these results whilst putting emphasis on in situ processing by a combined FIB and molecular beam epitaxy system. The typical performance of present FIB systems is also presented. In order to utilize the potential advantages of FIB processing, reduction of damage and improvement of throughput are important, and much effort has been devoted to developing processing techniques which require a reduced dose. The importance of low-energy FIB is discussed. (author)

This report consists of the notes distributed to the participants at the IEEE Mini-Course on Modern Plasma Diagnostics that was held in Madison, Wisconsin in May 1980. It presents an overview of Heavy IonBeam Probing that briefly describes the principles and discuss the types of measurements that can be made. The problems associated with implementing beam probes are noted, possible variations are described, estimated costs of present day systems, and the scaling requirements for large plasma devices are presented. The final chapter illustrates typical results that have been obtained on a variety of plasma devices. No detailed calculations are included in the report, but a list of references that will provide more detailed information is included

An electron beamion source (EBIS) for the production of low energy, multiply charged ionbeams to be used in atomic physics experiments has been designed and constructed. An external high perveance electron gun is used to launch the electron beam into a conventional solenoid. Novel features of the design include a distributed sputter ion pump to create the ultrahigh vacuum environment in the ionization region of the source and microprocessor control of the axial trap voltage supplies

This volume provides up to date information on the experimental, theoretical and technological aspects of film growth assisted by ionbeams.Ionbeam assisted film growth is one of the most effective techniques in aiding the growth of high-quality thin solid films in a controlled way. Moreover, ionbeams play a dominant role in the reduction of the growth temperature of thin films of high melting point materials. In this way, ionbeams make a considerable and complex contribution to film growth. The volume will be essential reading for scientists, engineers and students working in thi

Two new interdisciplinary programs are underway at Los Alamos involving the physics and technology of intense light ionbeams. In contrast to high-power ICF applications, the LANL effort concentrates on the development of relatively low-voltage (50 to 800 kV) and long-pulsewidth (0.1 to 1 μs) beams. The first program involves the 1.2 MV, 300-kJ Anaconda generator which has been fitted with an extractionion diode. Long pulsewidth ionbeams have been accelerated, propagated, and extracted for a variety of magnetic field conditions. The primary application of this beam is the synthesis of novel materials. Initial experiments on the congruent evaporative deposition of metallic and ceramic thin films are reported. The second program involves the development of a 120-keV, 50-kA, 1-μs proton beam for the magnetic fusion program as an ion source for an intense diagnostic neutral beam. Ultra-bright, pulsed neutral beams will be required to successfully measure ion temperatures and thermalized alpha particle energy distributions in large, dense, ignited tokamaks such as ITER

Two new interdisciplinary programs are underway at Los Alamos involving the physics and technology of intense light ionbeams. In contrast to high-power ICF applications, the LANL effort concentrates on the development of relatively low-voltage (50 to 800 kV) and long pulsewidth (0.1 to 1 μs) beams. The first program involves the 1.2 MV, 300-kJ Anaconda generator which has been fitted with an extractionion diode. Long pulsewidth ionbeams have been accelerated, propagated, and extracted for a variety of magnetic field conditions. The primary application of this beam is the synthesis of novel materials. Initial experiments on the congruent evaporative deposition of metallic and ceramic thin films are reported. The second program involves the development of a 120-keV, 50-kA, 1-μs proton beam for the magnetic fusion program as an ion source for an intense diagnostic neutral beam. Ultra-bright, pulsed neutral beams will be required to successfully measure ion temperatures and thermalized alpha particle distributions in large, dense, ignited tokamaks such as ITER

Calculations have shown that efficiently generated and focused ionbeams could have significant advantages over electron beams in achieving ignition of inertially-confined thermonuclear fuel. Efficient ionbeam generation implies use of a good ion source and suppression of net electron current. Net electron flow can be reduced by allowing electrons to reflex through a highly transparent anode or by use of transverse magnetic fields (either beam self-fields or externally applied fields). Geometric focusing can be achieved if the beam is generated by appropriately shaped electrodes. Experimental results are presented which demonstrate ionbeam generation in both reflexing and pinched-flow diodes. Spherically shaped electrodes are used to concentrate a proton beam, and target response to proton deposition is studied

For over decades, focused ionbeam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ionbeam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ionbeam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ionbeam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ionbeam with various ion species, a FEI two-lens electron (2LE) column for SEM imaging, and a five-axis manipulator system for sample positioning. An all-electrostatic two-lens column has been designed to focus the ionbeamextracted from the source. Based on the Munro ion optics simulation, beam spot sizes as small as 100 nm can be achieved at beam energies between 5 to 35 keV if a 5 (micro)m-diameter extraction aperture is used. Smaller beam spot sizes can be obtained with smaller apertures at sacrifice of some beam current. The FEI 2LE column, which utilizes Schottky emission, electrostatic focusing optics, and stacked-disk column construction, can provide high-resolution (as small as 20 nm) imaging capability, with fairly long working distance

The first beams of highly charged ions in Hungary were obtained in fall of 1996. The new 14.5 GHz ECR ion source of ATOMKI produced beams of multiply charged ions with remarkable intensities at first experiments. Since then, numerous further developments were carried out. An external electrondonor electrode drastically increased the plasma density and, consequently, the intensity of highly charged ions. These upgrades concentrated mainly on beams from gaseous elements and were carried out by the ECRIS team of ATOMKI. Another series of experiments - ionising from solids - however, was done in the framework of an international collaboration. The first metal ionbeam has been extracted from the ECRIS in November 1997 using the known method of Metal Ions from Volatile Compounds (MIVOC). The possibility to put the MIVOC chamber inside the ion source was also tested and the dosing regulation problem of metal vapours inside the ion source was solved. As a result, beams of more than 10 μA of highly charged Fe and Ni ions were produced. (author)

An overview of the use of stored ionbeams and phase space cooling (electron cooling) is given for the field of molecular physics. Emphasis is given to interactions between molecular ions and electrons studied in the electron cooler: dissociative recombination and, for internally excited molecular ions, electron-induced ro-vibrational cooling. Diagnostic methods for the transverse ionbeam properties and for the internal excitation of the molecular ions are discussed, and results for phase space cooling and internal (vibrational) cooling are presented for hydrogen molecular ions

Physical processes determining generation of ionbeams with high emission current density in electrohydrodynamic emitters are considered. Electrohydrodynamic effects developing in ion emission features and kinetics of ion interaction in beams with high density are discussed. Factors determining the size of the emission zone, emission stability at high and low currents, cluster generation, increase of energy spread and decrease of brightness are analyzed. Problems on practical provision of stable EHD emitter functioning are considered. 94 refs.; 8 figs.; 1 tab

Radioactive ionbeams are produced at INFN- Laboratori Nazionali del Sud (LNS) by means of the two operating accelerators, the Tandem and the Superconducting Cyclotron (CS), originally designed to accelerate stable beams. Both the ISOL (Isotope Separation On Line) and the IFF (In-Flight Fragmentation) methods are exploited to produce RIBs in two different ways at different energies: in the first case, the Cyclotron is the primary accelerator and the Tandem accelerates the secondary beams, while in the second case radioactive fragments are produced by the Cyclotron beam in a thin target with energies comparable to the primary beam energy. The ISOL facility is named EXCYT (Exotics at the Cyclotron and Tandem) and was commissioned in 2006, when the first radioactive beam ( 8 Li) has been produced. The IFF installation is named FRIBs (in Flight Radioactive IonBeams), and it has started to produce radioactive beams in 2001, placing a thin target in the extractionbeam line of the Cyclotron. The development of both facilities to produce and accelerate radioactive ionbeams at LNS, is briefly described, with some details on the future prospects that are presently under consideration or realization.

Transport of light ionbeams through low-pressure background gas is under investigation at NRL in support of the light-ion ICF program at Sandia National Laboratories. Scaling experiments and the field solver/orbit code ATHETA have been used to design and construct a focusing, extraction applied-B diode for transport experiments. An active anode source has been developed to provide a high proton fraction in the ionbeam and a fast ion turn-on time. A very sensitive Zeeman diagnostic is being developed to determine the net current distribution in the beam/transport system. Both analytical and numerical techniques using several codes are being applied to transport modeling, leading to the capability of full system studies. (author). 1 tab., 5 figs., 10 refs

Transport of light ionbeams through low-pressure background gas is under investigation at NRL in support of the light-ion ICF program at Sandia National Laboratories. Scaling experiments and the field solver/orbit code ATHETA have been used to design and construct a focusing, extraction applied-B diode for transport experiments. An active anode source has been developed to provide a high proton fraction in the ionbeam and a fast ion turn-on time. A very sensitive Zeeman diagnostic is being developed to determine the net current distribution in the beam/transport system. Both analytical and numerical techniques using several codes are being applied to transport modeling, leading to the capability of full system studies. (author). 1 tab., 5 figs., 10 refs.

Results of experiments performed in order to accelerate intense beams of light and heavier ions are presented. The accelerating diodes are driven by existing pulsed power generators. Optimization of the generator structure is described in chapter I. Nuclear diagnostics of the accelerated light ionbeams are presented in chapter II. Chapter III deals with the physics of intense charged particle beams. The models developed are applied to the calculation of the performances of the ion diodes described in the previous chapters. Chapter IV reports preliminary results on a multiply ionized carbon source driven by a 0.1 TW pulsed power generator. (author) [fr

The interaction of energetic electrons with highly charged ions is of great importance to several research fields such as astrophysics, laser fusion and magnetic fusion. In spite of this importance there are almost no measurements of electron interaction cross sections for ions more than a few times ionized. To address this problem an electron beamion trap (EBIT) is being developed at LLNL. The device is essentially an EBIS except that it is not intended as a source of extractedions. Instead the (variable energy) electron beam interacting with the confined ions will be used to obtain measurements of ionization cross sections, dielectronic recombination cross sections, radiative recombination cross sections, energy levels and oscillator strengths. Charge-exchange recombinaion cross sections with neutral gasses could also be measured. The goal is to produce and study elements in many different charge states up to He-like xenon and Ne-like uranium. 5 refs., 2 figs

The aim of this thesis is to improve the performance of a new shape cold cathode Penning ion source to be suitable for some applications. In this work, many trials have been made to reach the optimum dimensions of the new shape of cold Molybdenum cathode Penning ion source with radial extraction. The high output ionbeam can be extracted in a direction transverse to the discharge region. The new shape cold cathode Penning ion source consists of Copper cylindrical hollow anode of 40 mm length, 12 mm diameter and has two similar cone ends of 15 mm length, 22 mm upper cone diameter and 12 mm bottom cone diameter. The two movable Molybdenum cathodes are fixed in Perspex insulator and placed symmetrically at two ends of the anode. The Copper emission disc of 2 mm thickness and has central aperture of different diameters is placed at the middle of the anode for ionbeam exit. The inner surface of the emission disc is isolated from the anode by Perspex insulator except an area of diameter 5 mm to confine the electrical discharge in this area. A movable Faraday cup is placed at different distances from the emission electrode aperture and used to collect the output ionbeam from the ion source. The working gases are admitted to the ion source through a hole in the anode via a needle valve which placed between the gas cylinder and the ion source. The optimum anode- cathode distance, the uncovered area diameter of the emission disc, the central aperture diameter of the emission electrode, the distance between emission electrode and Faraday cup have been determined using Argon gas. The optimum distances of the ion source were found to be equal to 6 mm, 5 mm, 2.5 mm, and 3 cm respectively where stable discharge current and maximum output ionbeam current at low discharge current can be obtained. The discharge characteristics, ionbeam characteristics, and the efficiency of the ion source have been measured at different operating conditions and different gas pressures using

Intense Ion and Electron Beams treats intense charged-particle beams used in vacuum tubes, particle beam technology and experimental installations such as free electron lasers and accelerators. It addresses, among other things, the physics and basic theory of intense charged-particle beams; computation and design of charged-particle guns and focusing systems; multiple-beam charged-particle systems; and experimental methods for investigating intense particle beams. The coverage is carefully balanced between the physics of intense charged-particle beams and the design of optical systems for their formation and focusing. It can be recommended to all scientists studying or applying vacuum electronics and charged-particle beam technology, including students, engineers and researchers.

A beam-plasma type ion source employing an original operating principle has been developed by the present authors. The ion source consists of an ionextraction region with an electron gun, a thin long drift tube as the plasma production chamber, and a primary electron beam collector. An electron beam is effectively utilized for the dual purpose of high density plasma production as a result of beam-plasma discharge, and high current ionbeamextraction with ion space-charge compensation. A high density plasma of the order of 10 11 --10 13 cm -3 was produced by virtue of the beam-plasma discharge which was caused by the interaction between a space-charge wave on the electron beam and a high frequency plasma wave. The plasma density then produced was 10 2 --10 3 times the density produced only by collisional ionization by the electron beam. In order to obtain a stable beam-plasma discharge, a secondary electron beam emitted from the electron collector should be utilized. The mechanism of the beam-plasma discharge was analyzed by use of a linear theory in the case of the small thermal energy of the electron beam, and by use of a quasilinear theory in the case of the large thermal energy. High current ionbeams of more than 0.1 A were extracted even at a low extraction voltage of 1--5 kV

Ionbeam etching and deposition are normally carried out with beam, target and substrate potentials near ground potential. In this paper, the effects of intentional or unintentional changes in these potentials are described. Examples include beam neutralization, a single extraction grid, substrate bias, and target bias. Each example is described in terms of beam plasma parameters. (Auth.)

The results are presented of experimental efforts aimed at ionbeam current stabilization in an equipment for ion implantation in solids. The related problems of power supplies are discussed. Measured characteristics of laboratory equipment served the determination of the parameters to be required of the supplies as well as the design and the construction of the supplies. The respective wiring diagram is presented. (J.K.)

This invention relates to a method and system for enhancing the power-producing capability of a nuclear fusion reactor, and more specifically to methods and structure for enhancing the ion density in a directed particle fusion reactor. In accordance with the invention, oppositely directed ionbeams constrained to helical paths pass through an annular reaction zone. The object is to produce fusion reactions due to collisions between the ionbeams. The reaction zone is an annulus as between an inner-cylindrical electrode and an outer-cylindrical coaxial electrode. The beams are enhanced in ion density at spaced points along the paths by providing spline structures protruding from the walls of the electrodes into the reaction zone. This structure causes variations in the electric field along the paths followed by the ionbeams. Such fields cause the beams to be successively more and less concentrated as the beams traverse the reaction zone. Points of high concentration are the points at which fusion-producing collisions are most likely to take place

This book covers ionbeam application in modern materials research, offering the basics of ionbeam physics and technology and a detailed account of the physics of ion-solid interactions for ion implantation, ionbeam synthesis, sputtering and nano-patterning.

The detailed physics of ionbeamextraction from a plasma column by intense sinusoidal radio frequency (rf) electric fields at the ion cyclotron frequency omega/sub ci/ and its harmonics is experimentally studied. Results describe the instantaneous relationship - within one rf period of approx. = 3009 nsec - between applied rf, the plasma response and the ions expelled by rf and plasma fields. Reflex discharges in H 2 , D 2 , and He with ion and electron densities greater than or equal to10 11 cm -3 are subjected to 0-5 kV zero-to-peak rf electric fields E vector and 0.65-9.00 kG background magnetic fields B 0 vector with E vector perpendicular to B 0 vector. Ion currents up to 200 μA are extracted. Nonperturbing optical diagnostics measure the relative amplitude and phase of instantaneous ion and electron density fluctuations induced by the rf during each rf cycle and the time variation of extractedion bursts, the latter made possible by the use of a phosphor beam-stop. Detailed dependences on external electric and magnetic fields are reported. The plasma density fluctuations are in good agreement with the dispersion relation for electrostatic ion cyclotron waves (EICW), and the beam data show current enhancement at the second harmonic over that at the fundamental and evidence for a radically different mechanism for the rf-driven ionextraction process than conventional wisdom assumes. This work represents the first detailed, systematic study of the ac ionextraction process

At GSI - Helmholtz Centre for Heavy Ion Research in Darmstadt/Germany the HITRAP project is in the commissioning phase. This world-wide unique facility consists of a linear decelerator for heavy, highly charged ions including atomic physics precision experiments. During commissioning of the cavities, transverse emittances were measured using the single-shot pepperpot method as well as the multi-gradient method. The extraction emittance of the experimental storage ring (ESR) was determined. Furthermore, the phase space distribution of an decelerated beam at an intermediate energy of 500keV/u was measured behind the IH-structure. New algorithms have been integrated into the analysis of digital images. The longitudinal bunch structure measurements of the ionbeam at the entry point into the decelerator and the operation of the Double-drift Buncher is shown. The design, development and the first commissioning of a new single-shot pepperpot emittance meter for very low beam currents and beam energies in the order of some hundred nA is described, making it possible to measure the beam behind the deceleration cavities. In addition, transverse beam dynamics calculations were performed, which supported the hands-on commissioning of the accelerator. It is described how the entire beam line from the ESR to the radio-frequency quadrupole can be optimized using the new routine for transverse effects of the bunching and deceleration, which was successfully integrated into the software COSY Infinity. (orig.)

Beam optics in the extraction system of an ECR ion source (ECRIS) are examined both analytically and numerically, by taking nonlinear effect due to aberrations of einzel lens into account. It is shown that this effect can cause hollow beam formation. Simple analytical criteria to keep the good beam quality in the focusing system are given. (author)

The profile of an ionbeam produced in an Electron Cyclotron Resonance Ion Source (ECRIS) can vary greatly depending on the source settings and the ion-optical tuning. Strongly focussed ionbeams form circular structures (hollow beams) as predicted by simulations and observed in experiments. Each of the rings is predicted to be dominated by ions with same or at least similar m/q-ratios due to ion-optical effects. To check this we performed a series of preliminary investigations to test the required tuning capabilities of our ion source. This includes beam focussing (A) and beam steering (B) using a 3D-movable extraction. Having tuned the source to deliver a beam of strongly focussed ions of different ion species and having steered this beam to match the transmittance area of the sector magnet we also recorded the ion charge state distribution of the strongly focussed beam profile at different, spatially limited positions (C). The preliminary results will be introduced within this paper: it appears that our 3D-movable extraction is very efficient to steer and to focus the beam strongly. The paper is followed by the slides of the presentation. (authors)

KAERI has possessed design and fabrication technologies of various ion sources including Duoplasmatron and DuoPiGatron developed by R and D projects of the long-term nuclear technology development program. In order to industrialize ionbeam equipments utilizing these ion sources, a technology transfer project for a technology transfer project for a domestic firm has been performed. Under this project, engineers of the firm have been trained through classroom lectures of ionbeam principles and OJT, an ion/proton beam equipment (DEMO equipment) has been designed, assembled and commissioned jointly with the engineers. Quality of the ion sources has been quantified, and technologies for ionbeam equipment construction, functional test and application research have been developed. The DEMO equipment, which consists of an ion source, power supplies, vacuum, cooling and target systems, has been fabricated and tested to secure stability and reliability for industrial uses. Various characteristic tests including high voltage insulation, beamextraction, beam current measuring, etc. have been performed. This DEMO can be utilized for ion sources development as well as ionbeam process development for various industrial products. Engineers of the firm have been trained for the industrialization of ionbeam equipment and joined in beam application technology development to create industrial needs of beam equipment. (author)

A conceptual design of a neutral beam line based on the neutralization of negative deuterium ions is presented. This work is a detailed design of a complete neutral beam line based on using negative ions from a direct extraction source. Anticipating major technological advancements, beam line components have been scaled including the negative ion sources and components for the direct energy recovery of charged beams and high speed cryogenic pumping. With application to the next step in experimental fusion reactors (TNS), the neutral beam injector system that has been designed provides 10 MW of 200 keV neutral deuterium atoms. Several arms are required for plasma ignition

As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ionbeam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ionbeam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ionbeams of various elements, such as O2+, BF2+, P+ etc., for surface modification and doping applications. With optimized source condition, around 85% of BF2+, over 90% of O2+ and P+ have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ionbeam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He+beam is as high as 440 A/cm2 • Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O2+ionbeam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O2+ions with the dose of 1015 cm-2. The oxide can then serve as a hard mask for patterning of the Si film. The

As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ionbeam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ionbeam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ionbeams of various elements, such as O 2 + , BF 2 + , P + etc., for surface modification and doping applications. With optimized source condition, around 85% of BF 2 + , over 90% of O 2 + and P + have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ionbeam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He + beam is as high as 440 A/cm 2 · Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O 2 + ionbeam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O 2 + ions with the dose of 10 15 cm -2 . The oxide can then serve as a hard mask for patterning of the Si film. The process flow and the experimental results for directly patterned poly-Si features are presented. The formation of shallow pn-junctions in bulk silicon wafers by scanning focused P

In order to study the generation and extraction of negative ions for neutral beam injection application, a negative ion source is being designed and constructed at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). Through a four electrode grids system inside the accelerator, a negative ionbeam will be extracted and accelerated up to −60 kV on a reduced scale extraction area of 12 × 50 cm{sup 2} (the area of PG apertures is 185 cm{sup 2}). The beam optics is a key issue for the accelerator design, and greatly determine the source experimental performance in term of beam current, heat load on the grid, beam divergence, and so on. In this paper, the trajectories of electrons and negative ions were simulated in the electrode grids of the negative ion source. The filter capability of electron deflection magnet on the co-extracted electrons is evaluated and confirmed. The negative ionbeam optics was designed according to the calculated results of beam divergence and beam radius along the beamlet in different acceleration voltages. The deflection effect of the electron deflection magnet on the negative ionbeam was investigated in the single beamlet case and multi-beamlets case.

IonBeam Analysis: Fundamentals and Applications explains the basic characteristics of ionbeams as applied to the analysis of materials, as well as ionbeam analysis (IBA) of art/archaeological objects. It focuses on the fundamentals and applications of ionbeam methods of materials characterization.The book explains how ions interact with solids and describes what information can be gained. It starts by covering the fundamentals of ionbeam analysis, including kinematics, ion stopping, Rutherford backscattering, channeling, elastic recoil detection, particle induced x-ray emission, and nucle

In metals, the surface curvature dependence of the sputtering yield and the presence of an extra energy barrier whenever diffusing adatoms try to descend step edges, produce a similar surface instability, which builds up regular patterns. By tuning the competition between these two mechanisms, it is possible to create self-organized structures of the size of few nanometers. Height, lateral distance and order of the structures change with the deposition parameters like ion energy, dose, incident angle and substrate temperature. The paper offers an overview of the experiments carried out and foresees possible applications of these results in the area of material science

This book introduces materials scientists and designers, physicists and chemists to the properties of materials that can be modified by ion irradiation or implantation. These techniques can help design new materials or to test modified properties; novel applications already show that ion-beam techniques are complementary to others, yielding previously unattainable properties. Also, ion-beam interactions modify materials at the nanoscale, avoiding the often detrimental results of lithographic or chemical techniques. Here, the effects are related to better-known quasi-equilibrium thermodynamics, and the consequences to materials are discussed with concepts that are familiar to materials science. Examples addressed concern semiconductor physics, crystal and nanocluster growth, optics, magnetism, and applications to geology and biology.

This final report describes a ≤ 150kV, 40kA, 100ns high repetition rate pulsed power system and intense ionbeam source which is now in operation at Cornell University. Operation of the Magnetically-controlled Anode Plasma (MAP) ion diode at > 100Hz (burst mode for up to 10 pulse bursts) provides an initial look at repetition rate limitations of both the ion diode and beam diagnostics. The pulsed power systems are capable of ≥ 1kHz operation (up to 10 pulse bursts), but ion diode operation was limited to ∼100Hz because of diagnostic limitations. By varying MAP diode operating parameters, ionbeams can be extracted at a few 10s of keV or at up to 150keV, the corresponding accelerating gap impedance ranging from about 1Ω to about 10Ω. The ability to make hundreds of test pulses per day at an average repetition rate of about 2 pulses per minute permits statistical analysis of diode operation as a function of various parameters. Most diode components have now survived more than 10 4 pulses, and the design and construction of the various pulsed power components of the MAP diode which have enabled us to reach this point are discussed. A high speed data acquisition system and companion analysis software capable of acquiring pulse data at 1ms intervals (in bursts of up to 10 pulses) and processing it in ≤ min is described

A design is presented that suggests that a negative ion neutral beam based on direct extraction is applicable to TNS, assuming technological advancements in several areas. Improvements in negative ion sources, direct energy conversion of charged beams, and high speed cryogenic pumping are needed. The increase in efficiency over a positive ion system and the encouraging results of the first attempt at a total design justify increased effort in the development of the above mentioned areas

This thesis describes investigations on negative hydrogen ion sources at the ampere level. Formation of H - ions occurs when positive hydrogen ions capture two electrons at metal surfaces. The negative ionization probability of hydrogen at metal surfaces increases strongly with decreasing work function of the surface. The converters used in this study are covered with cesium. Usually there are 'surface plasma sources' in which the hydrogen source plasma interacts with a converter. In this thesis the author concentrates upon investigating a new concept that has converters outside the plasma. In this approach a positive hydrogen ionbeam is extracted from the plasma and is subsequently reflected from a low work function converter surface. (Auth.)

The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H(-)) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H(-) beamextraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H(-) beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.

Neutralization of the ionbeam charge and current is an important scientific issue for many practical applications. The process of ionbeam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ionbeam pulse are presented

Neutralization of the ionbeam charge and current is an important scientific issue for many practical applications. The process of ionbeam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ionbeam pulse are presented.

In order to study beam optics of NIRS-ECR ion source used in HIMAC, EGUN code has been modified to make it capable of modeling ionextraction from a plasma. Two versions of the modified code are worked out with two different methods in which 1-D and 2-D sheath theories are used respectively. Convergence problem of the strong nonlinear self-consistent equations is investigated. Simulations on NIRS-ECR ion source and HYPER-ECR ion source (in INS, Univ. of Tokyo) are presented in this paper, exhibiting an agreement with the experimental results. Some preliminary suggestions on the upgrading the extraction systems of these sources are also proposed. (author)

In order to study beam optics of NIRS-ECR ion source used in HIMAC, EGUN code has been modified to make it capable of modeling ionextraction from a plasma. Two versions of the modified code are worked out with two different methods in which 1-D and 2-D sheath theories are used respectively. Convergence problem of the strong nonlinear self-consistent equations is investigated. Simulations on NIRS-ECR ion source and HYPER-ECR ion source (in INS, Univ. of Tokyo) are presented in this paper, exhibiting an agreement with the experimental results. Some preliminary suggestions on the upgrading the extraction systems of these sources are also proposed. (author).

The implantation of polymers has received considerable attention in recent years, primarily to examine doping of conducting polymers and to increase the surface conductivity (by many orders of magnitude) of highly insulating polymers. The interest in these studies was partly motivated by possible applications to microelectronic device fabrication. More recently it has been observed that ion implantation can under some conditions lead to the formation of a hard (e.g. as hard as steel, ca. 3 MPa) and conducting surface layer. This paper will review the ionbeam modification of polymers resulting from ion implantation with reference to fundamental ion-solid interactions. This leads us to examine whether or not implantation of polymers is a contradiction in terms. (Author)

A specialized bioengineering ionbeam line has recently been completed at Chiang Mai University to meet rapidly growing needs of research and application development in low-energy ionbeam biotechnology. This beam line possesses special features: vertical main beam line, low-energy (30 keV) ionbeams, double swerve of the beam, a fast pumped target chamber, and an in-situ atomic force microscope (AFM) system chamber. The whole beam line is situated in a bioclean environment, occupying two stories. The quality of the ionbeam has been studied. It has proved that this beam line has significantly contributed to our research work on low-energy ionbeam biotechnology

The possibility of using intense bursts of heavy ions to initiate an inertially confined fusion reaction has stimulated interest in the transport of intense unneutralized heavy ionbeams by quadrupole or solenoid systems. This problem was examined in some detail, using numerical integration of the coupled envelope equations for the quadrupole case. The general relations which emerge are used to develop examples of high energy transport systems and as a basis for discussing the limitations imposed by a transport system on achievable intensities for initial acceleration

In order to understand the physics mechanism of a negative ionextraction in negative ion sources, an emission surface of the negative ions around an aperture at a plasma grid, so-called a meniscus, has been analyzed by an inverse calculation of the negative ion trajectory in a two dimensional beam analysis code. In this method, the meniscus is defined as the final position of the negative ion trajectories which are inversely calculated from the measured beam profile to the plasma grid. In a case of the volume-produced negative ions, the calculated meniscus by the inverse calculation was similar to that obtained in conventional beam simulation codes for positive ionextractions such as BEAMORBT and SLACCAD. The negative ion current density was uniform along the meniscus. This indicates that the negative ions produced in the plasma are transported to the plasma grid uniformly as considered in the transportation of the positive ions. However, in a surface production case of negative ions, where the negative ions are generated near the plasma grid with lower work function by seeding cesium, the current density in the peripheral region of the meniscus close to the plasma grid surface was estimated to be 2 times larger than the center region, which suggested that the extraction process of the surface-produced negative ions was much different with that for the positive ions. Because this non-uniform profile of the current density made the meniscus shape strongly concave, the beamextracted from the peripheral region could have a large divergence angle, which might be one of origins of so-called beam halo. This is the first results of the determination of the meniscus based on the experiment, which is useful to improve the prediction of the meniscus shape and heat loads based on the beam trajectories including beam halo.

The problem of matching an ionbeam delivered by a high-intensity ion source with an accelerator is considered. The experimental results of highly charged ionbeam transport with space-charge compensation by electrons are presented. A tungsten thermionic cathode is used as a source of electrons for beam compensation. An increase of ionbeam current density by a factor of 25 is obtained as a result of space-charge compensation at a distance of 3 m from the extraction system. The process of ionbeam space-charge compensation, requirements for a source of electrons, and the influence of recombination losses in a space-charge-compensated ionbeam are discussed. (author)

This report gives a series of helpful programs which are used in materials research with ionbeams. In this context algorithms which can substitute table books are dealt with. This is true for the programs DEDX and PRAL; they are used in order to determine the energy loss of ions in solid bodies, their working range and straggling. Furthermore, simulator routines and analyzers are described. The program TRIM simulates the physical phenomena which occur with the penetration of high-energy ions into solid bodies. In this context electronic excitations, phonons and lattice distortions which are caused by the ions are dealt with. For the experimental ion implantation it is interesting to know the final distribution of the simulated ions in the solid body. The program RBS simulates the Rutherford spectrum of ions which are scattered from a solid body which may consist of up to nine elements and up to one hundred layers. The unknown composition of a solid body can be determined in direct comparison with the experimental spectrum. The program NRA determines concentration and penetrative distribution of an impurity by means of the experimental nuclear reaction spectrum of this impurity. All programs are written in FORTRAN 77. (orig./MM) [de

By means of ionbeam atomizing or sputtering an integrally composed coating, the composition of which continuously changes from 100% of the substrate to 100% of the coating, can be surfaced on a substrate (e.g. molten quartz on plastic lenses). In order to do this in the facility there is directed a primary beam of accelerated noble gas ions on a target from the group of the following materials: SiO 2 , Al 2 O 3 , Corning Glass 7070, Corning Glass 7740 or borosilicate glass. The particles leaving the target are directed on the substrate by means of an acceleration potential of up to 10 KV. There may, however, be coated also metal layers (Ni, Co) on a mylar film resulting in a semireflecting metal film. (RW) [de

Conventional focused ionbeam systems employ a liquid-metal ion source (LMIS) to generate high-brightness beams, such as Ga + beams. Recently there has been an increased need for focused ionbeams in areas like biological studies, advanced magnetic-film manufacturing and secondary-ion mass spectroscopy (SIMS). In this article, status of development on focused ionbeam systems with ion species such as O 2 + , P + , and B + will be reviewed. Compact columns for forming focused ionbeams from low energy (∼3keV), to intermediate energy (∼35keV) are discussed. By using focused ionbeams, a SOI MOSFET is fabricated entirely without any masks or resist

A rf inductively coupled ion source employing a novel electrode assembly for focusing a broad ionbeam on a relatively small target area was developed. The primary application of this ion source is the deposition of thin films used in the fabrication of magnetic sensors and optical devices. The ion optics consists of a three-electrode set of multiaperture concave dished grids with a beamextraction diameter of 150 mm. Also described is a variation in the design providing a beamextraction diameter of 120 mm. Grid hole diameters and grid spacing were optimized for low beamlet divergence and low grid impingement currents. The radius of curvature of the grids was optimized to obtain an optimally focused ionbeam at the target location. A novel grid fabrication and mounting design was employed which overcomes typical limitations of such grid assemblies, particularly in terms of maintaining optimum beam focusing conditions after multiple cycles of operation. Ionbeam generation with argon and xenon gases in energy ranges from 0.3 to 2.0 keV was characterized. For operation with argon gas, beam currents greater than 0.5 A were obtained with a beam energy of 800 eV. At optimal beam formation conditions, beam profiles at distances about equal to the radius of curvature were found to be close to Gaussian, with 99.9% of the beam current located within a 150 mm target diameter. Repeatability of the beam profile over long periods of operation is also reported.

Image-projection ion-beam lithography is an attractive alternative for submicron patterning because it may provide high throughput; it uses demagnification to gain advantages in reticle fabrication, inspection, and lifetime; and it enjoys the precise deposition characteristics of ions which cause essentially no collateral damage. This lithographic option involves extracting low-mass ions (e.g., He + ) from a plasma source, transmitting the ions at low voltage through a stencil reticle, and then accelerating and focusing the ions electrostatically onto a resist-coated wafer. While the advantages of this technology have been demonstrated experimentally by the work of IMS (Austria), many difficulties still impede extension of the technology to the high-volume production of microelectronic devices. We report a computational study of a lithography system designed to address problem areas in field size, telecentricity, and chromatic and geometric aberration. We present a novel ion-column-design approach and conceptual ion-source and column designs which address these issues. We find that image-projection ion-beam technology should in principle meet high-volume-production requirements. The technical success of our present relatively compact-column design requires that a glow-discharge-based ion source (or equivalent cold source) be developed and that moderate further improvement in geometric aberration levels be obtained. Our system requires that image predistortion be employed during reticle fabrication to overcome distortion due to residual image nonlinearity and space-charge forces. This constitutes a software data preparation step, as do correcting for distortions in electron lithography columns and performing proximity-effect corrections. Areas needing further fundamental work are identified

A technique for ionbeam space-charge neutralization with pulsed electron beams is described. The intensity of multiply-charged ions produced with a laser ion source can be enhanced or decreased separately with electron beam trains of MHz repetition rate. These are generated with ferroelectric cathodes, which are pulsed in synchronization with the laser ion source. The pulsed electron beams guide the ionbeam in a similar way to the alternating gradient focusing of charged particle beams in circular accelerators such as synchrotrons. This new neutralization technology overcomes the Langmuir-Child space-charge limit and may in future allow ionbeam currents to be transported with intensities by orders of magnitude higher than those which can be accelerated today in a single vacuum tube. (author). 6 figs., 10 refs.

The ionization of residual gas by an electron beam in an accelerator generates ions that can resonantly couple to the beam through a wave propagating in the beam-ion system. Results of the study of a beam-ion instability are presented for a multi-bunch train taking into account the decoherence of ion oscillations due to the ion frequency spread and spatial variation of the ion frequency. It is shown that the combination of both effects can substantially reduce the growth rate of the instability. (author)

Ion implantation is the main application for high current heavy ionbeams. Transfer ratio is defined as the ratio of the total ion current leaving the ion source to the current delivered to the endstation. This ratio is monitored and logged and its importance is explained. It is also affected by other factors, such as the isotopic and molecular composition of the total ionbeam. The transfer ratio reveals the fraction of ions which are intercepted by parts of the beamline system. The effects of these ions are discussed in two categories: processing purity and reliability. In discussing the emittance of ribbon beams, the two orthogonal planes are usually considered separately. Longitudinal emittance is determined by slot length and by plasma ion temperature. It has already been revealed that the longitudinal divergence of the beams from BF3 is perhaps double that of the beam from arsenic vapour or argon, at the same total perveance from the ion source. This poses the question: why is the ion temperature higher for BF3 than for As or Ar? The transverse emittance is in practical terms dominated by the divergence. It is the most fruitful area for improvement in most real-world systems. There is an intrinsic divergence arising from initial ion energies within the plasma, and there is emittance growth that can occur as a result of aberration in the beamextraction optics. (N.K.)

The program at Donner Pavilion has applied nuclear medicine research to the diagnosis and radiosurgical treatment of life-threatening intracranial vascular disorders that affect more than half a million Americans. Stereotactic heavy-charged-particle Bragg peak radiosurgery, using narrow beams of heavy ions, demonstrates superior biological and physical characteristics in brain over X-and γ-rays, viz., improved dose distribution in the Bragg peak and sharp lateral and distal borders and less scattering of the beam. Examination of CNS tissue response and alteration of cerebral blood-flow dynamics related to heavy-ion Bragg peak radiosurgery is carried out using three-dimensional treatment planning and quantitative imaging utilizing cerebral angiography, computerized tomography (CT), magnetic resonance imaging (MRI), cine-CT, xenon X-ray CT and positron emission tomography (PET). Also under examination are the physical properties of narrow heavy-ionbeams for improving methods of dose delivery and dose distribution and for establishing clinical RBE/LET and dose-response relationships for human CNS tissues. Based on the evaluation and treatment with stereotactically directed narrow beams of heavy charged particles of over 300 patients, with cerebral angiography, CT scanning and MRI and PET scanning of selected patients, plus extensive clinical and neuroradiological followup, it appears that Stereotactic charged-particle Bragg peak radiosurgery obliterates intracranial arteriovenous malformations or protects against rebleeding with reduced morbidity and no mortality. Discussion will include the method of evaluation, the clinical research protocol, the Stereotactic neuroradiological preparation, treatment planning, the radiosurgery procedure and the protocol for followup. Emphasis will be placed on the neurological results, including the neuroradiological and clinical response and early and late delayed injury in brain leading to complications (including vasogenic edema

For the experimental fusion reactor ITER, which should show the feasibility of sustaining a fusion plasma with a positive power balance, some technology still has to be developed, amongst others also the plasma heating system. One heating technique is the neutral beam injection (NBI). A beam of fast deuterium atoms is injected into the fusion plasma. By heavy particle collisions the beam particles give their energy to the plasma. A NBI system consists of three major components. First, deuterium ions are generated in a low temperature, low pressure plasma of an ion source. At ITER, the requirements on the beam energy of 1 MeV cause the necessity of negative charged deuterium ions. Secondly, the ions are accelerated within an acceleration system with several grids, where the plasma grid is the first grid. The grids are on different descending high voltage potentials. The source itself is on the highest negative potential. Thirdly, the fast deuterium ions have to be neutralised. This thesis deals with the second step in the mentioned beam system, the ion acceleration and beam formation. The underlying experiments and measurements were carried out at the testbeds BATMAN (BAvarianTest MAchine for Negative ions) and ELISE (Extraction from a Large Ion Source Experiment) at the Max-Planck-Institut fuer Plasmaphysik Garching (IPP Garching). The main goal of this thesis is to provide a tool which allows the determination of the beam properties. These are beam divergence, stripping losses and beam inhomogeneity. For this purpose a particle trajectory code has been developed from scratch, namely BBC-NI (Bavarian Beam Code for Negative Ions). The code is able to simulate the whole beam and the outcome of several beam diagnostic tools. The data obtained from the code together with the measurements of the beam diagnostic tools should allow the reconstruction of the beam properties. The major beam diagnostic tool, which is used in this thesis, is the beam emission spectroscopy

This document presents the revised data taking schedule of NA61 with ionbeams. The revision takes into account limitations due to the new LHC schedule as well as final results concerning the physics performance with secondary ionbeams. It is proposed to take data with primary Ar and Xe beams in 2012 and 2014, respectively, and to test and use for physics a secondary B beam from primary Pb beam fragmentation in 2010, 2011 and 2013.

This type of dipole magnet was used in the extractedbeam lines of the North Area. It shows an opening for three different proton beam lines: a primary extracted proton beam, split by an upstream magnetic beam splitter (see photo 7612017) into three separated beams passes through different parts of its aperture: right, left up, left down. These magnets were designed to be concrete-insulated for radiation resistance. F. Streun stands on the right.

Observation of the effects of implants of energetic ions at high dose rates into Si have produced some exciting and interesting results. The mechanism whereby displacement damage produced by ions self-anneals during high dose rate implantation is discussed. It is shown that ionbeam annealing (IBA) offers in certain situations unique possibilities for damage annealing. Annealing results of the near surface in Si with a buried oxide layer, formed by high dose implantation, are presented in order to illustrate the advantages offered by IBA. It is also shown that ion irradiation can stimulate the epitaxial recrystallization of amorphous overlayers in Si. The nonequilibrium alloying which results from such epitaxial processes is discussed as well as mechanisms which limit the solid solubility during irradiation. Finally, a dose rate dependency for the production of stable damage by ion irradiation at a constant fluence has been observed. For low fluence implants, the amount of damage is substantially greater in the case of high flux rather than low flux implantation

The equations defining the ion density in a non-quasineutral plasma (chasma) are derived for a number of particular cases from the general results obtained in paper 1. Explicit calculations are made for a fairly general class of boundaries: all tri-axial ellipsoids, including cylinders with elliptic cross-section and the plane parallel case. The results are very simple. When the ion production and the beam intensity are constant then the steady state ion space charge is also constant in space, it varies over less than 10% for the various geometries, it may exceed the beam density largely for comparatively high pressures (usually still less than about 10 -3 Torr), it is tabulated for a number of interesting cases and moreover it can be calculated precisely and easily by some simple formulae for which also approximations are elaborated. The total potential is U =-ax 2 -by 2 -cz 2 , a, b and c constants which can be calculated immediately from the space charge density and the geometry; the largest coefficient varies at most over a factor four for various geometries; it is tabulated for a number of interesting cases. (author)

To improve the H(-) ionbeam optics, it is necessary to understand the energy relaxation process of surface produced H(-) ions in the extraction region of Cs seeded H(-) ion sources. Coulomb collisions of charged particles have been introduced to the 2D3V-PIC (two dimension in real space and three dimension in velocity space particle-in-cell) model for the H(-) extraction by using the binary collision model. Due to Coulomb collision, the lower energy part of the ion energy distribution function of H(-) ions has been greatly increased. The mean kinetic energy of the surface produced H(-) ions has been reduced to 0.65 eV from 1.5 eV. It has been suggested that the beam optics of the extracted H(-) ionbeam is strongly affected by the energy relaxation process due to Coulomb collision.

To understand the physical mechanism of the beam halo formation in negative ionbeams, a two-dimensional particle-in-cell code for simulating the trajectories of negative ions created via surface production has been developed. The simulation code reproduces a beam halo observed in an actual negative ionbeam. The negative ionsextracted from the periphery of the plasma meniscus (an electro-static lens in a source plasma) are over-focused in the extractor due to large curvature of the meniscus.

To understand the physical mechanism of the beam halo formation in negative ionbeams, a two-dimensional particle-in-cell code for simulating the trajectories of negative ions created via surface production has been developed. The simulation code reproduces a beam halo observed in an actual negative ionbeam. The negative ionsextracted from the periphery of the plasma meniscus (an electro-static lens in a source plasma) are over-focused in the extractor due to large curvature of the meniscus.

The particle-in-cell code Warp has been enhanced to incorporate both two- and three-dimensional sheath extraction models giving Warp the capability of simulating entire ionbeam transport systems including the extraction of beams from plasma sources. In this article we describe a method of producing initial ion distributions for plasma extraction simulations in electron cyclotron resonance (ECR) ion sources based on experimentally measured sputtering on the source biased disc. Using this initialization method, we present preliminary results for extraction and transport simulations of an oxygen beam and compare them with experimental beam imaging on a quartz viewing plate for the superconducting ECR ion source VENUS

Mass analyzed highly charged ionbeams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ionbeam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

In Part One they formulate in a general way the problem of analyzing and evaluating the aberrations of quadrupole magnet beam systems, and of characterizing the shapes and other properties of the beam envelopes in the neighborhood of foci. They consider all aberrations, including those due to misalignments and faulty construction, through third order in small parameters, for quadrupole beam systems. One result of this study is the development of analytic and numerical techniques for treating these aberrations, yielding useful expressions for the comparison of the aberrations of different beam systems. A second result of this study is a comprehensive digital computer program that determines the magnitude and nature of the aberrations of such beam systems. The code, using linear programming techniques, will adjust the parameters of a beam system to obtain specified optical properties and to reduce the magnitude of aberrations that limit the performance of that system. They examine numerically, in detail, the aberrations of two typical beam systems. In Part Two, they examine the problem of extracting the proton beam from a synchrotron of 'H' type magnet construction. They describe the optical studies that resulted in the design of an external beam from the Bevatron that is optimized with respect to linear, dispersive, and aberration properties and that uses beam elements of conservative design. The design of the beam is the result of the collaboration of many people representing several disciplines. They describe the digital computer programs developed to carry out detailed orbit studies which were required because of the existence of large second order aberrations in the beam.

The results of investigation are briefly reviewed in the field of ion optic fusion performed at the Institute of Nuclear Research in Swierk. The ion optic fusion concept is based on the possibility of obtaining fusion energy at highly ordered motion of ions in counterstreaming ionbeams. For this purpose TW ionbeams must be produced and focused. To produce dense and charge-neutralized ionbeams the selective conductivity and ballistic focusing ideas were formulated and used in a series of RPI devices with low-pressure cylindrical discharge between grid-type electrodes. 100 kA, 30 keV deuteron beams were successfully produced and focused into the volume of 1 cm 3 , yielding 10 9 neutrons per 200 ns shot on a heavy ice target. Cylindrically convergent ionbeams with magnetic anti-defocusing were proposed in order to reach a positive energy gain at reasonable energy level. (J.U.)

A new low energy ionbeam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ionbeams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ionbeams. Higher emittance at low energy of intense ionbeam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ionbeam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ionbeams similar to the trend observed theoretically.

Discussed are the results of investigation of plasma properties recieved by neutralization of intensive ionbeam space charge. Considered is the process of ionbeam compensation by charges, formed as a result of gas ionization by this beam or by externally introduced ones. Emphasis is placed on collective phenomena in ion-beam plasma, in particular on non-linear effects limiting amplitude of oscillations. It is shown, that not only dinamic decompensation but the Coulomb collisions of ions with electrons as well as other collective oscillations significantly affects the propagation of compensated ionbeams. All the processes are to be taken into account at solving the problem of obtaining ''superdense'' compensated beams

Discussed are the results of investigation of plasma properties received by neutralization of intense ionbeam space charge. Considered is the process of ionbeam compensation by charges, formed as a result of gas ionization by this beam or by externally introduced ones. Emphasis is placed on collective phenomena in ion-beam plasma, in particular on non-linear effects limiting amplitude of oscillations. It is shown that not only dynamic decompensation but the Coulomb collisions of ions with electrons as well as other collective oscillations significantly affects the propagation of compensated ionbeams. All the processes are to be taken into account in solving the problem of obtaining ''superdense'' compensated beams.

For the purpose of improvement of the pinched electron beam diode, the production of an ionbeam by a diode with electrodes in a conical shape was studied at low voltage operation (--200 kV). The ionbeam is emitted from a small region of the diode apex. The mean ionbeam current density near the axis at 12 cm from the diode apex is two or three times that from an usual flat parallel diode with the same dimension and impedance. The brightness and the power brightness at the otigin are 450 MA/cm 2 sr and 0.12 TW/cm 2 sr respectively. (author)

The nitrocarburization of the AISI-H13 tool steel by ionbeam assisted deposition is reported. In this technique, a carbon film is continuously deposited over the sample by the ionbeam sputtering of a carbon target while a second ion source is used to bombard the sample with low energy nitrogen ions. The results show that the presence of carbon has an important impact on the crystalline and microstructural properties of the material without modification of the case depth

The beam-plasma instability is analyzed for the ionbeams used for neutral beam generation. Both positive and negative ionbeams are considered. Stability is predicted when the beam velocity is less than the electron thermal velocity; the only exception occurs when the electron density accompanying a negative ionbeam is less than the ion density by nearly the ratio of electron to ion masses. For cases in which the beam velocity is greater than the electron thermal velocity, instability is predicted near the electron plasma frequency

The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G. G. Kelley and O. B. Morgan. We describe the ion sources under development at this Laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field.......Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field....

A high-current H - ionbeam has been accelerated with the two-stage acceleration. A large negative hydrogen ion source with an external magnetic filter produces more than 10 A of the H - ions from the grid area of 25cm x 50cm with the arc efficiency of 0.1 A/kW by seeding a small amount of cesium. The H - ion current increases according to the 3/2-power of the total beam energy. A 13.6 A of H - ionbeam has been accelerated to 125 keV at the operational gas pressure of 3.4 mTorr. The optimum beam acceleration is achieved with nearly the same electric fields in the first and the second acceleration gaps on condition that the ratio of the first acceleration to the extraction electric fields is adjusted for an aspect ratio of the extraction gap. The ratio of the acceleration drain current to the H - ion current is more than 1.7. That is mainly due to the secondary electron generated by the incident H - ions on the extraction grid and the electron suppression grid. The neutralization efficiency was measured and agrees with the theoretical calculation result. (author)

In ionbeam analysis (IBA) the depth profiles are extracted from the experimentally determined energy profiles. The spectra, however, are subject to finite energy resolution of both extrinsic and intrinsic origin. Calculation of those effects such as instrumental beam, geometry and detection-related energy and angular spreads as well as energy straggling, multiple scattering and Doppler effects in the sample itself is not trivial, especially since it involves treatment of non-independent random processes. A proper account for energy spread is vital in IBA not only for correct extraction of elemental and isotopic depth profiles from the measured spectra, but already prior to data acquisition, in optimising experimental conditions to reach the required depth resolution at a certain depth. After a short review of the literature on the different energy spread contributions experimental examples are given from resonance, RBS, elastic BS and ERDA practice in which an account for energy spread contributions is essential. Some further examples illustrate extraction of structural information (roughness, pore size, etc.) from elaborated depth resolution calculation for such layer structures

In ionbeam analysis (IBA) the depth profiles are extracted from the experimentally determined energy profiles. The spectra, however, are subject to finite energy resolution of both extrinsic and intrinsic origin. Calculation of those effects such as instrumental beam, geometry and detection-related energy and angular spreads as well as energy straggling, multiple scattering and Doppler effects in the sample itself is not trivial, especially since it involves treatment of non-independent random processes. A proper account for energy spread is vital in IBA not only for correct extraction of elemental and isotopic depth profiles from the measured spectra, but already prior to data acquisition, in optimising experimental conditions to reach the required depth resolution at a certain depth. After a short review of the literature on the different energy spread contributions experimental examples are given from resonance, RBS, elastic BS and ERDA practice in which an account for energy spread contributions is essential. Some further examples illustrate extraction of structural information (roughness, pore size, etc.) from elaborated depth resolution calculation for such layer structures.

A meniscus of plasma-beam boundary in H - ion sources largely affects the extracted H - ionbeam optics. Although it is hypothesized that the shape of the meniscus is one of the main reasons for the beam halo observed in experiments, a physical mechanism of the beam halo formation is not yet fully understood. In this letter, it is first shown by the 2D particle in cell simulation that the H - ionsextracted from the periphery of the meniscus cause a beam halo since the surface produced H - ions penetrate into the bulk plasma, and, thus, the resultant meniscus has a relatively large curvature.

A measuring station has been built at the CRYRING heavy ion accelerator to test the Single Event Upset (SEU) phenomena in working Static RAM circuits. The setup extracts the beam using Rutherford scattering and the ions are monitored with a BaF sub 2 scintillator. SEU measurements have been performed for standard bulk CMOS memory circuits.

The Holifield Radioactive IonBeam Facility now under construction at the Oak Ridge National Laboratory will use the 25 MV tandem accelerator for the acceleration of radioactive ionbeams to energies appropriate for research in nuclear physics; negative ionbeams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ionbeams to negative ionbeams, both positive and negative ion sources are viable options for use at the facility. The choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. Although direct-extraction negative ion sources are clearly desirable, the ion formation efficiencies are often too low for practical consideration; for this situation, positive ion sources, in combination with charge exchange, are the logical choice. The high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the facility because of its low emittance, relatively high ionization efficiencies, and species versatility, and because it has been engineered for remote installation, removal, and servicing as required for safe handling in a high-radiation-level ISOL facility. The source will be primarily used to generate ionbeams from elements with intermediate to low electron affinities. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are under design consideration for generating radioactive ionbeams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report

Recent progress in the radiation effects of ionbeams on polymers are reviewed briefly. Our recent work on the radiation effects of ionbeams on polystyrene thin films on silicon wafers and time resolved emission studies on polymers are described. (orig.)

Energetic ionbeam irradiation is the basis of a wide plethora of powerful research- and fabrication-techniques for materials characterisation and processing on a nanometre scale. This book is suitable for practitioners, researchers and graduate students working in the field of ionbeams and application

Hitachi has developed several new technologies for the synchrotron and its related system to realize reliable and flexible operation of a proton therapy system. Especially important among them are a non-resonant RF acceleration cavity using FINEMET core with multiple power feeding and radio frequency driven beamextraction technique (RF-DE) for a synchrotron. Various treatment operations such as variable acceleration energy or respiration gating became possible and simple due to the above technique. For beam transport, a beam steering method for the beam, using transfer matrix realizes quick and precise correction of the beam orbit. A compact microwave ion source has also been developed for the injector to obtain further higher reliability and availability. Most of these technologies are also effective to enhance the reliability and flexibility of other ionbeam therapy systems

The ability of plasmas to etch deep, small-scale features in materials is limited by localized charging of the features. The features charge because of the difference in electron and ion anisotropy, and thus one solution now being explored is to use ion-ion plasmas in place of electron-ion plasmas. Ion-ion plasmas are effectively electron-free and consist mainly of positive and negative ions. Since the two ion species behave similarly, localized charging is largely eliminated. However, the only way to produce ion-ion plasmas at low gas pressure is to convert electrons into negative ions through two-body attachment to neutrals. While the electron attachment rate is large at low electron temperatures (Te < 1 eV) in many of the halogen gases used for processing, these temperatures occur in most reactors only during the afterglow when the heating fields are turned off and the plasma is decaying. By contrast, Te is low nearly all the time in plasmas produced by electron beams, and therefore electron beams can potentially produce ion-ion plasmas continuously. The theory of ion-ion plasmas formed by pulsed electron beams is examined in this talk and compared with experimental results presented elsewhere [1]. Some general limitations of ion-ion plasmas, including relatively low flux levels, are discussed as well. [1] See the presentation by D. Leonhardt et al. at this conference.

A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ionbeam. The pure carbon ionbeam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ionbeam. The pure carbon ionbeam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

Full Text Available The need to extract the maximum beam intensity with low transversal emittance often comes with the drawback of operating the ion source to limits where beam current instabilities arise, such fluctuations can change the beam properties producing a mismatch in the following sections of the machine. The space charge compensation (SCC generated by the beam particles colliding with the residual gas reaches a steady state after a build-up time. This paper shows how once in the steady state, the beam ends with a transversal emittance value bigger than the case without compensation. In addition, we study how the beam intensity variation can disturb the SCC dynamics and its impact on the beam properties. The results presented in this work come from 3-D simulations using tracking codes taking into account the secondary ions to estimate the degree of the emittance growth due to space charge and SCC.

The use of intense pulsed ionbeams is providing a new capability for surface engineering based on rapid thermal processing of the top few microns of metal, ceramic, and glass surfaces. The IonBeam Surface Treatment (IBEST) process has been shown to produce enhancements in the hardness, corrosion, wear, and fatigue properties of surfaces by rapid melt and re-solidification. A new code called IBMOD was created, enabling the modeling of intense ionbeam deposition and the resulting rapid thermal cycling of surfaces. This code was used to model the effect of treatment of aluminum, iron, and titanium using different ion species and pulse durations. (author). 3 figs., 4 refs.

The effect of ionbeams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ionbeams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ionbeams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ionbeams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

The effect of ionbeams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ionbeams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ionbeams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ionbeams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

We are developing an embodiment of metal vapor vacuum arc (Mevva) ion source which will operate dc and have very large area beam. In preliminary testing, a dc titanium ionbeam was formed with a current of approximately 0.6 amperes at an extraction voltage of 9kV (about 18 keV ion energy, by virtue of the ion charge state distribution) and using an 18 cm diameter set of multi-aperture. Separately, we have tested and formed beam from a 50 cm diameter (2000 cm 2 ) set of grids using a pulsed plasma gun. This configuration appears to be very efficient in terms of plasma utilization, and we have formed beams with diameter 33 cm (FWHM) and ion current up to 7 amperes at an extraction voltage of 50 kV (about 100 keV mean ion energy) and up to 20 amperes peak at the current overshoot part of the beam pulse. Here we describe this Part Of our Mevva development program and summarize the results obtained to-date

According to the characteristic of high current negative ionbeamextraction and acceleration system for negative ion-based neutral beam injector, a numerical simulation model and a calculation code of the negative ionbeam system are established in order to assist the design of the system. The movement behavior of the negative ionbeam and accompanying electron beam in joint effect of the electric and magnetic field of the system is calculated. The effect of relative parameters on the negative ionbeam optics characteristic is investigated, such as beam density, negative ion initial temperature and stripping losses, final electrode aperture displacement. The electromagnetic configuration in the system is optimized. The initial optimized results for the 300 kV, 5 electrodes negative ionbeam system show that the magnetic field of this system can deflect the electron beam to the extraction electrode as electron acceptor at lower energy and that assuming 20% stripping losses of the H - ion in extraction region and 21 mA ·cm -2 extracted H - beam density, the r.m.s. divergence angle of all output beam lets and divergence angle of 85% output beam lets are 0.327 deg. and 0.460 deg., respectively

The intense synchrotron radiation beams from the NSLS uv or x-ray storage rings still do not compare in monochromatized photon flux with a laser beam, a fact which becomes apparent in considering reaction rates for interaction of photon and ionbeams. There are two prototypical interaction geometries, parallel and perpendicular. Calculations should properly be done in the rest frame of the ionbeam; however, expected beta values are small, so the lab frame will be employed and aberration and Doppler shift effects neglected

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

While beam loss issues have hardly been considered in detail for heavy ion fusion scenarios, recent heavy ion machine developments in different labs (European Organization for Nuclear Research (CERN), Gesellschaft fur Schwerionenforschung (GSI), Institute for Theoretical and Experimental Physics (ITEP), Relativistic Heavy-Ion Collider (RHIC)) have shown the great importance of beam current limitations due to ion losses. Two aspects of beam losses in heavy ion accelerators are theoretically considered: (1) secondary neutron production due to lost ions, and (2) vacuum pressure instability due to charge exchange losses. Calculations are compared and found to be in good agreement with measured data. The application to a Heavy-Ion Driven Inertial Fusion (HIDIF) scenario is discussed. 12 Refs.

A pulsed high voltage ion source is considered for use in ionbeam processing for the surface modification of materials, and deposition of conducting films on different substrates. The source consists of an Arkad'ev-Marx high voltage generator, a vacuum ion diode based on explosive ion emission, and a vacuum chamber as substrate holder. The ion diode allows conducting films to be deposited from metal or allow sources, with ionbeam mixing, onto substrates held at a pre-selected temperature. The main variables can be set in the ranges: voltage 100-700 kV, pulse length 0.3 μs, beam current 1-200 A depending on the ion chosen. The applications of this technology are discussed in semiconductor, superconductor and metallizing applications as well as the direction of future development and cost of these devices for commercial application. 14 refs., 6 figs

Cobalt alloy ion sources have been developed for silicide formation by focused ionbeam implantation. Four eutectic alloys AuCo, CoGe, CoY and AuCoGe were produced by electron beam welding. The AuCo liquid alloy ion source was investigated in detail. We have measured the emission current stability, the current-voltage characteristics, and the mass spectrum as a function of the mission current. (author) 1 fig., 2 refs.

High ionbeam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

Light ion sources are currently being studied to assess their ability to drive an inertial confinement fusion reactor. The author has produced a high purity, 1MV, 300A/cm 2 lithium beam using a 200cm 2 extraction geometry, magnetically insulated ion diode. The lithium source was an AC glow discharge cleaned, LiF/Al film active anode. The active anode plasma was formed after 50KA of current was shunted through the anode film for 20ns. The stoichiometry of the resulting ionbeam was 65% Li + , 20% Al +2 , and 15% H + . Without the glow discharge cleaning, the ionbeam was over 55% hydrogen and only 20% Li + . At the time of the diode's design, extraction diodes were producing poor ionbeams: their current efficiency was only 60-70%, and their extractedion current was radially nonuniform. This diode was the first high efficiency extraction diode, and produced over 200KA of ions with 80-90% ion current efficiency. In addition, by varying the tilt of the applied magnetic field, it was possible to show that the ion current density could be made independent of radius. Since the author was unable to make a Li + beam with a passive anode, he installed an active anode that used an external current to vaporize a thin metal film on the anode surface. Poor beam purity was the most serious problem with active anodes. In order to remove impurities, especially the hydrogen contamination, the author cleaned the anodes with a glow discharge. Al film anodes were cleaned with a 110mA, 33W DC glow discharge, and the LiF/Al film anodes were cleaned with an equivalent AC discharge. The results obtained and a model for the mechanism behind the cleaning process are throughly discussed

Some properties of the ionbeam produced by pinched electron beam diode having conical shape electrodes and organic insulator anode was studied. Ion energy is about 200keV and the peak diode current is about 30 kA. At 11cm from the diode apex, not the geometrical focus point, concentrated ionbeam was obtained. Its density is more than 500A/cm 2 . The mean ion current density within the radius of 1.6cm around the axis from conical diode is two or three times that from an usual pinched electron beam diode with flat parallel electrodes of same dimension and impedance under the same conditions. (author)

The Heavy Ion Fusion group at Lawrence Berkeley Laboratory has constructed the One Ampere Cesium Injector as a proof of principle source to supply an induction linac with a high charge density and high brightness ionbeam. This is studied here. An electron beam probe was developed as the major diagnostic tool for characterizing ionbeam space charge. Electron beam probe data inversion is accomplished with the EBEAM code and a parametrically adjusted model radial charge distribution. The longitudinal charge distribution was not derived, although it is possible to do so. The radial charge distribution that is derived reveals an unexpected halo of trapped electrons surrounding the ionbeam. A charge fluid theory of the effect of finite electron temperature on the focusing of neutralized ionbeams (Nucl. Fus. 21, 529 (1981)) is applied to the problem of the Cesium beam final focus at the end of the injector. It is shown that the theory's predictions and assumptions are consistent with the experimental data, and that it accounts for the observed ionbeam radius of approx. 5 cm, and the electron halo, including the determination of an electron Debye length of approx. 10 cm

An intense neutralized ionbeam can be injected and trapped in magnetic mirror or tokamak geometry. The details of the process involve beam polarization so that the beam crosses the fringing fields without deflection and draining the polarization when the beam reaches the plasma. Equilibrium requires that a large betatron field be added in tokamak geometry. In mirror geometry a toroidal field must be added by means of a current along the mirror axis. In either case, the geometry becomes that of the modified betatron which has been studied experimentally and theoretically in recent years. We consider beams of d and t ions with a mean energy of 500 kev and a temperature of about 50 kev. The plasma may be a proton plasma with cold ions. It is only necessary for beam trapping or to carry currents. The ion energy for slowing down is initially 500 kev and thermonuclear reactions depend only on the beam temperature of 50 kev which changes very slowly. This new configuration for magnetic confinement fusion leads to an energy gain of 10--20 for d-t reactions whereas previous studies of beam target interaction predicted a maximum energy gain of 3--4. The high beam energy available with pulsed ion diode technology is also essential for advanced fuels. 16 refs., 3 figs

A visual diagnostic technique has been developed to monitor and study ionbeam structure shape and size along a transport line. In this technique, a commercially available fluorescent screen is utilized in conjunction with a video camera. This visual representation of the beam structure is digitized and enhanced through use of false-color coding and displayed on a TV monitor for on-line viewing. Digitized information is stored for further off-line processing (e.g., extraction of beam profiles). An optional wire grid placed upstream of the fluor screen adds the capability of transverse emittance (or angular spread) measurement to this technique. This diagnostic allows real-time observation of the beam response to parameter changes (e.g., evolution of the beam structure, shifts in the beam intensity at various spatial locations within the beam perimeter, and shifts in the beam center and position). 3 refs., 5 figs

The cyclotron plasma-are source (PIG), duoplasmatron (DP), laser source (LS), electron beamion source (EBIS) and electron cyclotron resonance source (ECRS) from the viewpoint of generating intense and high charge state beams are considered. It is pointed out that for the last years three types of multicharged ion sources-EBIS, ECR and LS have been essentially developed. In the EBIS source the Xe 48+ ions are produced. The present day level of the development of the electron-beam ionization technique shows that by means of this technique intensive uranium nuclei beams production becomes a reality. On the ECR source Xe 26+ approximately 4x10 10 h/s, Asub(r)sup(12+) approximately 10 12 h/s intensive ionbeams are produced. In the laser source a full number of C 6+ ions during one laser pulse constitutes not less than 10 10 from the 5x10mm 2 emission slit. At the present time important results are obtained pointing to the possibility to separate the ion component of laser plasma in the cyclotron central region. On the PIG source the Xe 15+ ion current up to 10μA per pulse is produced. In the duoplasmatron the 11-charge state of xenon ionbeams is reached [ru

The negative ion source test facility ELISE (Extraction from a Large Ion Source Experiment) is in operation since beginning of 2013 at the Max-Planck-Institut für Plasmaphysik (IPP) in Garching bei München. The large radio frequency driven ion source of ELISE is about 1×1 m 2 in size (1/2 the ITER source) and can produce a plasma for up to 1 h. Negative ions can be extracted and accelerated by an ITER-like extraction system made of 3 grids with an area of 0.1 m 2 , for 10 s every 3 minutes. A total accelerating voltage of up to 60 kV is available, i.e. a maximum ionbeam power of about 1.2 MW can be produced. ELISE is equipped with several beam diagnostic tools for the evaluation of the beam characteristics. In order to evaluate the beam properties with a high level of detail, a sophisticated diagnostic calorimeter has been installed in the test facility at the end of 2013, starting operation in January 2014. The diagnostic calorimeter is split into 4 copper plates with separate water calorimetry for each of the plates. Each calorimeter plate is made of 15×15 copper blocks, which act as many separate inertial calorimeters and are attached to a copper plate with an embedded cooling circuit. The block geometry and the connection with the cooling plate are optimized to accurately measure the time-averaged power of the 10 s ionbeam. The surface of the blocks is covered with a black coating that allows infrared (IR) thermography which provides a 2D profile of the beam power density. In order to calibrate the IR thermography, 48 thermocouples are installed in as many blocks, arranged in two vertical and two horizontal rows. The paper describes the beam calorimetry in ELISE, including the methods used for the IR thermography, the water calorimetry and the analytical methods for beam profile evaluation. It is shown how the maximum beam inhomogeneity amounts to 13% in average. The beam divergence derived by IR thermography ranges between 1° and 4° and

Development of intense pulsed heavy ionbeam accelerator technology is described for the application of materials processing. Gas puff plasma gun and vacuum arc discharge plasma gun were developed as an active ion source for magnetically insulated pulsed ion diode. Source plasma of nitrogen and aluminum were successfully produced with the gas puff plasma gun and the vacuum arc plasma gun, respectively. The ion diode was successfully operated with gas puff plasma gun at diode voltage 190 kV, diode current 2.2 kA and nitrogen ionbeam of ion current density 27 A/cm 2 was obtained. The ion composition was evaluated by a Thomson parabola spectrometer and the purity of the nitrogen ionbeam was estimated to be 86%. The diode also operated with aluminum ion source of vacuum arc plasma gun. The ion diode was operated at 200 kV, 12 kA, and aluminum ionbeam of current density 230 A/cm 2 was obtained. The beam consists of aluminum ions (Al (1-3)+ ) of energy 60-400 keV, and protons (90-130 keV), and the purity was estimated to be 89%. The development of the bipolar pulse accelerator (BPA) was reported. A double coaxial type bipolar pulse generator was developed as the power supply of the BPA. The generator was tested with dummy load of 7.5 ohm, bipolar pulses of -138 kV, 72 ns (1st pulse) and +130 kV, 70 ns (2nd pulse) were successively generated. By applying the bipolar pulse to the drift tube of the BPA, nitrogen ionbeam of 2 A/cm 2 was observed in the cathode, which suggests the bipolar pulse acceleration. (author)

The former Berlin electron-beamion trap (EBIT) was moved to Greifswald. In addition to x-ray studies the setup will be used for the investigation of interaction processes between highly charged ions and atomic clusters such as charge exchange and fragmentation. The EBIT setup has now been reassembled and highly charged ions have been produced from Xe-Ar gas mixtures to study the ‘sawtooth effect’. In addition, the layout of the extraction beamline, the interaction region and product analysis for interaction studies with highly charged ions are presented.

A non-invasive diagnostic method for the experimental determination of the transverse profile of an intense ionbeam has been developed and investigated theoretically as well as experimentally within the framework of the present work. The method is based on the deflection of electrons when passing the electromagnetic field of an ionbeam. To achieve this an electron beam is employed with a specifically prepared transversal profile. This distinguish this method from similar ones which use thin electron beams for scanning the electromagnetic field [Roy et al. 2005; Blockland10]. The diagnostic method presented in this work will be subsequently called ''Electron-Beam-Imaging'' (EBI). First of all the influence of the electromagnetic field of the ionbeam on the electrons has been theoretically analyzed. It was found that the magnetic field causes only a shift of the electrons along the ionbeam axis, while the electric field only causes a shift in a plane transverse to the ionbeam. Moreover, in the non-relativistic case the magnetic force is significantly smaller than the Coulomb one and the electrons suffer due to the magnetic field just a shift and continue to move parallel to their initial trajectory. Under the influence of the electric field, the electrons move away from the ionbeam axis, their resulting trajectory shows a specific angle compared to the original direction. This deflection angle practically depends just on the electric field of the ionbeam. Thus the magnetic field has been neglected when analysing the experimental data. The theoretical model provides a relationship between the deflection angle of the electrons and the charge distribution in the cross section of the ionbeam. The model however only can be applied for small deflection angles. This implies a relationship between the line-charge density of the ionbeam and the initial kinetic energy of the electrons. Numerical investigations have been carried out to clarify the

Thin films of bio-inert (TiO 2+α, Al 2O 3+α) and bio-active (compounds of calcium and phosphorus oxides, hydroxyapatite) were deposited on the most commonly used implant materials such as titanium and stainless steel, using a dual-ion-beam deposition system. Rutherford backscattering spectroscopy was carried out for quantitative measurement of the interfacial atomic mixing and the composition of the elements. The experimental results show that by controlling the ionbeam energy and current, thin films with very good mechanical properties are obtained as a result of the ionbeam mixing within the film and at the interface of the film and substrate.

30 keV and 200 keV gas cluster ionbeam equipments have been developed for industrial applications. A gas cluster source with a non-cooled nozzle was used for both the equipments. Sufficient monomer ion suppression was achieved by using an ExB filter and chromatic lenses mass filter with low extraction voltage. These equipments are suitable to be used for low-damage surface treatment of metals, insulators and semiconductors without heavy metal contamination. (orig.)

We evaluate the feasibility of producing and using atomically neutral heavy ionbeams produced from negative ions as drivers for an inertial confinement fusion reactor. Bromine and iodine appear to be the most attractive elements for the driver beams. Fluorine and chlorine appear to be the most appropriate feedstocks for initial tests of extractable negative ion current densities. With regards to ion sources, photodetachment neutralizers, and vacuum requirements for accelerators and beam transport, this approach appears feasible within existing technology, and the vacuum requirements are essentially identical to those for positive ion drivers except in the target chamber. The principal constraint is that this approach requires harder vacuums in the target chamber than do space-charge-neutralized positive ion drivers. With realistic (but perhaps pessimistic) estimates of the total ionization cross section, limiting the ionization of a neutral beam to less than 5% while traversing a four -meter path would require a chamber pressure of no more than 5 x 10 -5 torr. Alternatively, even at chamber pressures that are too high to allow propagation of atomically neutral beams, the negative ion approach may still have appeal, since it precludes the possibly serious problem of electron contamination of a positive ionbeam during acceleration, drift compression, and focusing

The evolution of the electromagnetic ionsbeam instability driven by the reflected ion component backstreaming away from the earth's how shock into the foreshock region is studied by means computer simulation. The linear the quasi-linear states of the instability are found to be in good agreement with known results for the resonant model propagating parallel to the beam along the magnetic field and with theory developed in this paper for the nonresonant mode, which propagates antiparallel to the beam direction. The quasi-linear stage, which produces large amplitude 8Bapprox.B, sinusoidal transverse waves and ''intermediate'' ion distribution, is terminated by a nonlinear phase in which strongly nonlinear, compressive waves and ''diffuse'' ion distributions are produced. Additional processes by which the diffuse ions are accelerated to observed high energies are not addressed. The results are discussed in terms of the ion distributions and hydromagnetic waves observed in the foreshock of the earth's bow shock and of interplanetary shocks

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ionbeam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

This ion source was to be purchased from ANAC, Inc., a New Zealand-based supplier of beam optics hardware and atomic beam polarized ion sources in December 1982. Shortly before scheduled delivery ANAC went into receivership. During 1983 little work was done on the project as various steps were taken by us, first to get the ion source completed at ANAC, and then, failing that, to obtain the existing parts. In early 1984 we began work to finish the ion source in Seattle. The project is nearly complete, and this article presents progress to date. 2 refs

An important difference between monomer ionbeams and heavy molecular beams is a significant reduction in beam angular divergence and increased on-wafer angular accuracy for molecular beams. This advantage in beam quality stems from a reduction in space-charge effects within the beam. Such improved angular accuracy has been shown to have a significant impact on the quality and yield of transistor devices [1,12]. In this study, B 18 H x + beam current and angular divergence data collected on a hybrid scanned beam line that magnetically scans the beam across the wafer is presented. Angular divergence is kept below 0.5 deg from an effective boron energy of 200 eV to 3000 eV. Under these conditions, the beam current is shown analytically to be limited by space charge below about 1 keV, but by the matching of the beam emittance to the acceptance of the beam line above 1 keV. In addition, results of a beam transport model which includes variable space charge compensation are presented, in which a drift mode B 18 H x + beam is compared to an otherwise identical boron beam after deceleration. Deceleration is shown to introduce significant space-charge blow up resulting in a large on-wafer angular divergence. The divergence effects introduced by wafer charging are also discussed.

The suit of techniques (RBS, STIM, ERDS, PIXE, IL, IF,…) available in ionbeam analysis yields a variety of rich information. Typically, after the initial challenge of acquiring data we are then faced with the task of having to extract relevant information or to present the data in a format with the greatest impact. This process sometimes requires developing new software tools. When faced with such situations the usual practice at the Centre for IonBeam Applications (CIBA) in Singapore has been to use our computational expertise to develop ad hoc software tools as and when we need them. It then became apparent that the whole ionbeam community can benefit from such tools; specifically from a common software toolset that can be developed and maintained by everyone with freedom to use and allowance to modify. In addition to the benefits of readymade tools and sharing the onus of development, this also opens up the possibility for collaborators to access and analyse ionbeam data without having to depend on an ionbeam lab. This has the virtue of making the ionbeam techniques more accessible to a broader scientific community. We have identified ImageJ as an appropriate software base to develop such a common toolset. In addition to being in the public domain and been setup for collaborative tool development, ImageJ is accompanied by hundreds of modules (plugins) that allow great breadth in analysis. The present work is the first step towards integrating ionbeam analysis into ImageJ. Some of the features of the current version of the ImageJ ‘ion beam’ plugin are: (1) reading list mode or event-by-event files, (2) energy gates/sorts, (3) sort stacks, (4) colour function, (5) real time map updating, (6) real time colour updating and (7) median and average map creation

The suit of techniques (RBS, STIM, ERDS, PIXE, IL, IF,…) available in ionbeam analysis yields a variety of rich information. Typically, after the initial challenge of acquiring data we are then faced with the task of having to extract relevant information or to present the data in a format with the greatest impact. This process sometimes requires developing new software tools. When faced with such situations the usual practice at the Centre for IonBeam Applications (CIBA) in Singapore has been to use our computational expertise to develop ad hoc software tools as and when we need them. It then became apparent that the whole ionbeam community can benefit from such tools; specifically from a common software toolset that can be developed and maintained by everyone with freedom to use and allowance to modify. In addition to the benefits of readymade tools and sharing the onus of development, this also opens up the possibility for collaborators to access and analyse ionbeam data without having to depend on an ionbeam lab. This has the virtue of making the ionbeam techniques more accessible to a broader scientific community. We have identified ImageJ as an appropriate software base to develop such a common toolset. In addition to being in the public domain and been setup for collaborative tool development, ImageJ is accompanied by hundreds of modules (plugins) that allow great breadth in analysis. The present work is the first step towards integrating ionbeam analysis into ImageJ. Some of the features of the current version of the ImageJ ‘ion beam’ plugin are: (1) reading list mode or event-by-event files, (2) energy gates/sorts, (3) sort stacks, (4) colour function, (5) real time map updating, (6) real time colour updating and (7) median and average map creation.

The paper summarizes the studies on accelerated ionbeams at ATOMKI and their technical background, their use from chemical analysis to biological, medical, geological, archaeological applications, their advance from material science to micromachining. (TRA)

The subject of this review paper is the field of intense pulsed ionbeam generation and the potential application of the beams to fusion research. Considerable progress has been made over the past six years. The ion injectors discussed utilize the introduction of electrons into vacuum acceleration gaps in conjunction with high voltage pulsed power technology to achieve high output current. Power levels from injectors exceeding 1000 MW/cm 2 have been obtained for pulse lengths on the order of 10 -7 sec. The first part of the paper treats the physics and technology of intense ionbeams. The second part is devoted to applications of intense ionbeams in fusion research. A number of potential uses in magnetic confinement systems have been proposed

The ionbeam techniques used in studies of arts and archaeology are compared with other analytical techniques. Some examples are specially selected to illustrate the achievements and trends of the techniques in this field

The production of secondary radioactive beams at GANIL using the LISE spectrometer is reviewed. The experimental devices, and secondary beam characteristics are summarized. Production of neutron rich secondary beams was studied for the systems Ar40 + Be at 44 MeV/u, and 018 + Be at 45 and 65 MeV/u. Partial results were also obtained for the system Ne22 + Ta at 45 MeV/u. Experiments using secondary beams are classified into two categories: those which correspond to fast transfer of nuclei from the production target to a well shielded observation point; and those in which the radioactive beam interacts with a secondary target

We present the conclusions of the RSRE programme on the application of focused ionbeams in microelectronics and review the literature published in this field. We discuss the design and performance of focused beam implanters and the viability of their application to semiconductor device fabrication. Applications in the areas of lithography, direct implantation and micromachining are discussed in detail. Comparisons are made between the use of focused ionbeams and existing techniques for these fabrication processes with a strong emphasis placed on the relative throughputs. We present results on a novel spot size measurement technique and the effect of beam heating on resist. We also present the results of studies into implantation passivation of resist to oxygen plasma attack as basis for a dry development lithography scheme. A novel lithography system employing flood electron exposure from a photocathode which is patterned by a focused ionbeam which can also be used to repair mask defects is considered. (author)

Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ionbeams, and polarized alkali vapor targets can be used to produce polarized H - or 3 He - ionbeams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ionbeams with emphasis on the production of polarized negative ionbeams

The first clinical trial of heavy ion radiation therapy is scheduled in 1994 by using the heavy ion medical accelerator in Chiba (HIMAC). In order to start the clinical trial, first, it is necessary to know the physical characteristics of high energy heavy ions in human bodies, for example, dose and linear energy transfer (LET) distribution. Also the knowledge on the biological effectiveness of heavy ions is required. Based on these biophysical properties of heavy ions, monoenergetic heavy ionbeam should be modulated so as to make the spread Bragg peak suitable to heavy ion radiation therapy. In order to establish a methodology to obtain the most effective spread Bragg peak for heavy ion radiation therapy, a heavy ion irradiation port at the RIKEN ring cyclotron facility was constructed. By using a 135 MeV/u carbon beam, the biophysical properties of the heavy ions were investigated, and a range modulator was designed to have uniform biological response in the spread Bragg peak. The physical and biological rationality of the spread Bragg peak were investigated. The dose, LET and biological effect of a monoenergetic heavy ionbeam, the design of the range modulator, and the distributions of LET and biological dose for the spread Bragg peak are reported. (K.I.)

Interest in the use of an induction linac to accelerate heavy ions for the purpose of providing the energy required to initiate an inertially confined fusion reaction has stimulated a theoretical effort to investigate various beam dynamical effects associated with high intensity heavy ionbeams. This paper presents a summary of the work that has been done so far; transverse, longitudinal and coupled longitudinal transverse effects are discussed

The motion of ions passing from the homogeneous magnetic field into a conical one is treated analytically in paraxial approximation. Further ions transform into neutral particles at the recharging target which is placed in the conical area of field. The optimal conditions for maximum compression of the beams of neutral particles are investigated. An influence of the initial angular spread on the beam compression is analysed. The computation results together with the those of analytical treatment are presented

An ionbeam pulse radiolysis system has been constructed at HIMAC facility. Ionbeam of 24 MeV He{sup 2+} with the duration longer than 1 {mu}s is available for irradiation. Three kinds of aqueous solutions, (C{sub 6}H{sub 5}){sub 2}CO, NaHCO{sub 3} and KSCN, were irradiated and the absorption signals were observed. (author)

Full Text Available Recent years have seen a great potential of the focused ionbeam (FIB technology for the nanometer-scale patterning of a freestanding two-dimensional (2D layer. Experimentally determined sputtering yields of the perforation process can be quantitatively explained using the binary collision theory. The main peculiarity of the interaction between the ionbeams and the suspended 2D material lies in the absence of collision cascades, featured by no interaction volume. Thus, the patterning resolution is directly set by the beam diameters. Here, we demonstrate pattern resolution beyond the beam size and precise profiling of the focused ionbeams. We find out that FIB exposure time of individual pixels can influence the resultant pore diameter. In return, the pore dimension as a function of the exposure dose brings out the ionbeam profiles. Using this method of determining an ion-beam point spread function, we verify a Gaussian profile of focused gallium ionbeams. Graphene sputtering yield is extracted from the normalization of the measured Gaussian profiles, given a total beam current. Interestingly, profiling of unbeknown helium ionbeams in this way results in asymmetry of the profile. Even triangular beam shapes are observed at certain helium FIB conditions, possibly attributable to the trimer nature of the beam source. Our method of profiling ionbeams with 2D-layer perforation provides more information on ionbeam profiles than the conventional sharp-edge scan method does.

A dedicated National Centre for RIB (NCRIB) proposed discussed at several forums is presented. The production of (RIB) radioactive ionbeams and applications of beams leading to competitive studies in nuclear structure, nuclear reactions, condensed matter, bio-science and radioactive isotope production etc. are mentioned

A zeolite ion source has been developed for plasma diagnostics. Extractedbeam current is increased by a factor of ∼10 after redesigning the ion source structure and improving the method to make emitter material (zeolite). The paper introduces an experiment on making desirable ion emitter, together with properties of the newly developed ion source. (author)

The Argonne Tandem Linac Accelerator System (ATLAS) facility at Argonne National Laboratory provides a wide range of accelerated heavy ions from the periodic table. Frequently, the beam delivery rate of 12 MHz is too fast for the type of experiment on line. Reaction by-products from a target bombardment may have a decay interval much longer than the dead time between beam bunches. To prevent data from being corrupted by incoming ions a beam sweeper was developed which synchronously eliminates selected beam bunches to suit experimental needs. As the SWEEPER is broad band (DC to 6 MHz) beam delivery rates can be instantaneously changed. Ionbeam bunches are selectively kicked out by an electrostatic dipole electrode pulsed to 2 kVDC. The system has been used for almost three years with several hundred hours of operating time logged to date. Beam bunch delivery rates of 6 MHz down to 25 kHz have been provided. Since this is a non-resonant system any beam delivery rate from 6 MHz down to zero can be set. In addition, burst modes have been used where beam is supplied in 12 MHz bursts and then shut down for a period of time set by the user. 3 figs

Purpose: To develop a flexible pencil beam algorithm for helium ionbeam therapy. Dose distributions were calculated using the newly developed pencil beam algorithm and validated using Monte Carlo (MC) methods. Methods: The algorithm was based on the established theory of fluence weighted elemental pencil beam (PB) kernels. Using a new real-time splitting approach, a minimization routine selects the optimal shape for each sub-beam. Dose depositions along the beam path were determined using a look-up table (LUT). Data for LUT generation were derived from MC simulations in water using GATE 6.1. For materials other than water, dose depositions were calculated by the algorithm using water-equivalent depth scaling. Lateral beam spreading caused by multiple scattering has been accounted for by implementing a non-local scattering formula developed by Gottschalk. A new nuclear correction was modelled using a Voigt function and implemented by a LUT approach. Validation simulations have been performed using a phantom filled with homogeneous materials or heterogeneous slabs of up to 3 cm. The beams were incident perpendicular to the phantoms surface with initial particle energies ranging from 50 to 250 MeV/A with a total number of 10{sup 7} ions per beam. For comparison a special evaluation software was developed calculating the gamma indices for dose distributions. Results: In homogeneous phantoms, maximum range deviations between PB and MC of less than 1.1% and differences in the width of the distal energy falloff of the Bragg-Peak from 80% to 20% of less than 0.1 mm were found. Heterogeneous phantoms using layered slabs satisfied a {gamma}-index criterion of 2%/2mm of the local value except for some single voxels. For more complex phantoms using laterally arranged bone-air slabs, the {gamma}-index criterion was exceeded in some areas giving a maximum {gamma}-index of 1.75 and 4.9% of the voxels showed {gamma}-index values larger than one. The calculation precision of the

The Thales diagnostic equipment for ionbeam characterization consists of a gridded and single orifice retarding potential analyzer (RPA) and an energy selective mass spectrometer (ESMS). During the development phase of these sensors considerable effort was put into the removal of ion optical

In order to clarify transmission properties of an ionbeamextracted with various capillaries into the air, we have measured intensity distributions for the core and the halo components of MeV ionbeams using various capillaries. In addition, we have performed in-air-RBS and in-air-PIXE from the point of the application. At the conference, progress report of transmission properties of ionbeams with various capillaries and its applications will be presented.

The sources of information presented are essentially taken from the papers reported at several international seminars and those appeared in the Journal of Nuclear Instruments and Methods in Physics Research. Production and usage of radioactive ionbeams (RIB) in research have received the attention of scientists all over the world during the past six years. The first radioactive ionbeams ( 19 Ne) were produced at Bevalac for the purpose of medical research using a primary beam of energy 800 MeV/a.m.u. (author). 19 refs., 2 figs., 3 tabs

The barium ionbeam Zeeman diagnostic is an in situ nonperturbing diagnostic designed to measure both the plasma electric and magnetic fields in devices such as STM and EBT. The diagnostic satisfies the requirements of high precision, spatial resolution and nonperturbation of the plasma. The technique uses resonance absorption of light from a single moded laser in a beam of energetic barium ions to measure the Zeeman effect in the absorption spectrum (to measure changes in the magnetic field) and to observe the changes in beam velocity by the Doppler shift of the absorption lines

High-intensity pulsed ionbeam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extractingionbeam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ionbeam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ionbeam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ionbeam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ionbeam neutralization during propagation.

Progress is reported in the following areas of this research program: relative biological effectiveness and oxygen enhancement ratio of silicon ionbeams; heavy ion effects on the cell cycle; the potentiation effect (2 doses of high LET heavy-ion radiations separated by 2 to 3 hours); potentially lethal damage in actively growing cells and plateau growth cells; radiation induced macromolecular lesions and cellular radiation chemistry; lethal effects of dual radiation; and the development of a biophysical repair/misrepair model

The authors are using collinear laser excitation of fast ionbeams to study a number of atomic structure problems. The problems include the determination of fine and hyperfine structure in light positive and negative ions, plus measurements of absolute wavelengths of light from two-electron ions. In addition the authors intend to use a similar experimental arrangement to study excitation and decay of high Rydberg states first in the absence of fields and then in crossed electric and magnetic fields

Recent advances in broad-beam, ion-source technology are summarized, including low-energy ion optics, improved extraction grid fabrication, a compact ion-source design and a gridless ion-source design. Recent applications have emphasized concepts such as stress modification of vapor deposited films, very low energy ionbeams to minimize the physical sputtering portion in reactive etching, and the use of multiple sources and targets to sputter deposit alloys and compounds. A comprehensive critical review by the same authors appears concurrently, describing in detail the developments in broad-beam, ion-source technology 1 and the applications of these sources. 2

For silicon membranes irradiated by an ionbeam in a vacuum environment, such as the masks used for ionbeam lithography and the membranes used for thin film self-annealing, the heat transfer modes are radiation and limited conduction through the thin membrane. The radiation component depends on the total hemispherical emissivity which varies with the thickness and temperature of the membrane. A semiempirical correlation for the absorption coefficient of high resistivity silicon was derived and the variation of the total emissivity with temperature was computed for membranes with thicknesses between 0.1 and 10 μm. Based on this result, the temperatures reached during exposure to ionbeams of varying intensities were computed. A proper modeling of the emissivity is shown to be important for beam heating of thin silicon membranes. (orig.)

The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extractedbeam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

Two alternative discharge structures, which are both convenient for the extraction of broad and reactive ionbeams, are described. They have been designed in order to overcome both lifetime and beam contamination problems while preserving a high ionization efficiency and a smooth plasma uniformity. They both use a hot cathode duoplasmatron discharge to inject ionizing electrons into the main ionization chamber, according to the triplasmatron concept. The triplasmatron multipolar ion source (TMIS) uses the magnetic multipolar containment of both electrons and ions, whereas the triplasmatron reflex ion source (TRIS) uses the electrostatic and geometric containment of the ionizing electrons. The behaviour and performance of both structures are reported and discussed with a special emphasis to the operation with either oxygen or fluorocarbon gases. (author)

this problem, we have validated and scaled our design calculations with performance parameters of the Neutral Beam Injector at IPP, Julich, Germany. The performance test of the SST-1 PINI ion source was done at MARION Test Stand at IPP, Julich. Analyses of these results indicate that the measured power profile and the optical parameters of the beam are in good agreement with the simulation results. These parameters are stable over the beam pulse of 14s with extractedbeam energy of 31 MJ at 41 kV. This paper presents these results and details out future work need to be done in order to assess the steady state stability of the beam parameters.

On the 25th July 1986 the first 2,8 μA 66 MeV proton beam was successfully extracted from the separated sector cyclotron (SSC) at the National Accelerator Centre at Faure, South Africa. The beam has now also been transported for the first time down the high-energy beamline up to the last Faraday cup in front of the neutron therapy vault. A brief description of the extraction system of the SSC, consisting of an electrostatic extraction channel and two septum magnets is given

The authors have made and operated a very broad beam version of vacuum arc ion source and used it to carry out high energy metal ion implantation of a particularly large substrate. A multiple-cathode vacuum arc plasma source was coupled to a 50 cm diameter beam extractor (multiple aperture, accel-decel configuration) operated at a net extraction voltage of up to 50 kV. The metal ion species chosen were Ni and Ta. The mean ion charge state for Ni and Ta vacuum arc plasmas is 1.8 and 2.9, respectively, and so the mean ion energies were up to about 90 and 145 keV, respectively. The ion source was operated in a repetitively pulsed mode with pulse length 250 μs and repetition rate several pulses per second. The extractedbeam had a gaussian profile with FWHM about 35 cm, giving a nominal beam area of about 1,000 cm 2 . The current of Ni or Ta metal ions in the beam was up to several amperes. The targets for the ion implantation were a number of 24-inch long, highly polished Cu rails from an electromagnetic rail gun. The rails were located about 80 cm away from the ion source extractor grids, and were moved across a diameter of the vessel in such a way as to maximize the uniformity of the implant along the rail. The saturation retained dose for Ta was limited to about 4 x 10 16 cm -2 because of the rather severe sputtering, in accordance with the theoretical expectations for these implantation conditions. Here they describe the ion source, the implantation procedure, and the kinds of implants that can be produced in this way

A method to split off a few percent of the 6 x 10 13 AGS beam delivered to the Slow External Beam (SEB) lines and send it down the Fast External Beam line (FEB) has been developed. The mission is to feed a counter experiment off the FEB that directly measures the neutrino mass using the muon storage ring. The use of normal thin septum splitters would have an excessive loss overhead and been optically difficult. The AGS Slow Extraction uses a third integer resonance with sextuple strength so the resonance width is a few percent of the beam width. This results in a low density tail which will be clipped by a bent crystal and deflected into the FEB channel. This clipping off of the tail should reduce losses in the SEB transport line. Details of modeled orbits, particle distribution and extraction trajectories into and out off the crystal will be given

Full Text Available The study of an ionbeam transport mechanism contributes to the production of a good quality ionbeam with a higher current and better beam emittance. The simulation of an ionbeam provides the basis for optimizing the extraction system and the acceleration gap for the ion source. In order to extract an ionbeam from an ion source, a carefully designed electrode system for the required beam energy must be used. In our case, a self-extracted penning ion source is used for ion generation, extraction and acceleration with a single accelerating gap for the production of neutrons. The characteristics of the ionbeamextracted from this ion source were investigated using computer code SIMION 8.0. The ion trajectories from different locations of the plasma region were investigated. The simulation process provided a good platform for a study on optimizing the extraction and focusing system of the ionbeam transported to the required target position without any losses and provided an estimation of beam emittance.

A gas filled tube used to produce a neutron flux with the D(T,He/sup 4/)n reaction is described. Deuterium and tritium ions generated in a reflex discharge are extracted and accelerated to 100 keV by means of an accelerator electrode onto a deutero-tritide target electrode. The electrodes are designed to focus the ionbeam onto the target. Total tube currents consisting of extractedions, unsuppressed secondary electrons, and ions generated by interactions with the background gas are typically 100 mA. The characteristics of the extractedionbeam are discussed. Accelerating voltages greater than 50 kV are required to focus the beam through the accelerator aperture for configurations that give beams with the proper energy density onto the target. The perveance of the beam is discussed. Maximum perveance values are 2 to 20 nanopervs. Tube focusing and neutron production characteristics are described.

The ionbeam generation in a high current diode with anode plasma slab was studied. The ions were extracted from the anode plasma by the strong electric field of a deep potential well (virtual cathode), arising after the propagation of relativistic electrons through the anode plasma slab. The movement of this potential well with the front part of the ionbeam leads to collective ion acceleration up to the 10 MeV energy range. (author). 7 figs., 5 refs

Two main methods are used to produce radioactive ionbeams: -) the ISOL method (isotope separation on-line) in which the stable beam interacts with a thick target, the reaction products diffuse outside the target and are transferred to a source where they are ionized, a mass separator and a post-accelerator drive the selected radioactive ions to the right energy; -) the in-flight fragmentation method in which the stable beam interacts with a thin target, the reaction products are emitted from the target with a restricted angular distribution and a velocity close to that of the incident beam, the experimenter has to take advantage from the reaction kinetics to get the right particle beam. Characteristic time is far longer with the ISOL method but the beam intensity is much better because of the use of a post-accelerator. In both cases, the beam intensity is lower by several orders of magnitude than in the case of a stable beam. This article presents all the constraints imposed by radioactive beams to the detection systems of the reaction products and gives new technical solutions according to the type of nuclear reaction studied. (A.C.)

A method of ion acceleration in modulated electron beams is considered. Electron density and energy of their rotational motion are relatively low. However the effective ion-accelerating field is not less than 10 MeV/m. The electron and ion numbers in an individual bunch are also relatively small, although the number of produced bunches per time unit is great. Some aspects of realization of the method are considered. Possible parameters of the accelerator are given. At 50 keV electron energy and 1 kA beam current a modulation is realized at a wave length of 30 cm. The ion-accelerating field is 12 MeV/m. The bunch number is 2x10 3 in one pulse at a gun pulse duration of 2 μs. With a pulse repetition frequency of 10 2 Hz the number of accelerated ions can reach 10 13 -10 14 per second

The nitridation of vanadium by ionbeam irradiation is studied by the ion implantation method and the dynamic mixing method. The nitrogen ion implantation was carried out into deposited V(110) films. Using both methods, three phases are formed, i.e. α-V, β-V 2 N, and δ-VN. Which phases are formed is related to the implantation dose or the arrival ratio. The orientation of the VN films produced by the dynamic ionbeam mixing method is (100) and that of the VN films produced by the ion implantation method is (111). The nitridation of vanadium is also discussed in comparison with that of titanium and chromium. ((orig.))

Tailoring of nanostructures with energetic ionbeams has become an active area of research leading to the fundamental understanding of ion-solid interactions at nanoscale regime and with possible applications in the near future. Rutherford backscattering spectrometry (RBS), high resolution transmission electron microscopy (HRTEM) and asymmetric X-ray Bragg-rocking curve experimental methods have been used to characterize ion-induced effects in nanostructures. The possibility of surface and sub-surface/interface alloying at nano-scale regime, ion-beam induced embedding, crater formation, sputtering yield variations for systems with isolated nanoislands, semi-continuous and continuous films of noble metals (Au, Ag) deposited on single crystalline silicon will be reviewed. MeV-ion induced changes in specified Au-nanoislands on silicon substrate are tracked as a function of ion fluence using ex situ TEM. Strain induced in the bulk silicon substrate surface due to 1.5 MeV Au 2+ and C 2+ ionbeam irradiation is determined by using HRTEM and asymmetric Bragg X-ray rocking curve methods. Preliminary results on 1.5 MeV Au 2+ ion-induced effects in nanoislands of Co deposited on silicon substrate will be discussed

A new type of microwave ion source in which a permanent magnet generates an axially directed magnetic field needed for the electron cyclotron resonance was developed. The electron cyclotron resonance produces a high density plasma in the ion source. A mA-order ionbeam can be extracted. Compared with usual microwave ion sources, this source has a distinguished feature in that the axially directed magnetic field is formed by use of a permanent magnet. Shape of magnetic force lines near the ionextraction aperture was carefully investigated. The extractedion current as a function of the ionextraction voltage was measured. The experimental data are in good agreement with the theoretical line. The ion source can be heated up to 500 deg C, and extraction of the alkaline metal ions is possible. The extractedion current for various elements are shown in the table. The current density normalized by the proton was 350-650 mA/cm 2 which was nearly equal to the upper limit of the extractable positive ion current density. The plasma density was estimated and was 2 - 3 x 10 12 cm -3 . The mass spectrum of a Cesium ionbeam was obtained. A negligible amount of impurities was observed. The emittance diagram of the extractedionbeam was measured. The result shows that a low emittance and high brightness ion source is constructed. (Kato, T.)

Laser ion acceleration provides access to ion sources with unique properties. To use these capabilities the LIGHT collaboration (Laser Ion Generation Handling and Transport) was founded. The aim of this collaboration is the beam transport and manipulation of laser accelerated ions with conventional accelerator structures. Therefor a dedicated beam line has been build up at GSI Helmholtzzentrum fuer Schwerionenforschung. With this beam line the manipulation of the transversal and also the longitudinal beam parameters has been achieved. It has been shown that laser generated ionbeams can be transported over more than 6 meters and pulses shorter than 300 ps can be generated at this distance. This Talk will give an overview over the recent developments and plans of the LIGHT collaboration.

One approach being explored as a route to practical fusion energy uses heavy ionbeams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ionbeams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters

An investigation was made on characteristics of ionbeams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ionbeams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M 1 lines. Thus, ionbeams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by γirradiation, indicating that ionbeams could produce a variety of mutants with the same phenotype. In conclusion, ionbeams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and γ-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ionbeams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

An investigation was made on characteristics of ionbeams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ionbeams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M{sub 1} lines. Thus, ionbeams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by {gamma}irradiation, indicating that ionbeams could produce a variety of mutants with the same phenotype. In conclusion, ionbeams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and {gamma}-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ionbeams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

General trends in integrated circuit technology toward smaller device dimensions, lower thermal budgets, and simplified processing steps present severe physical and engineering challenges to ion implantation. These challenges, together with the need for physically based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in Si. In this article, we review the current status and future trends in ion implantation of Si at low and high energies with particular emphasis on areas where recent advances have been made and where further understanding is needed. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. Developments in the use of ionbeams for analysis indicate much progress has been made in one-dimensional analysis, but that severe challenges for two-dimensional characterization remain. The breadth of ionbeams in the semiconductor industry is illustrated by the successful use of focused beams for machining and repair, and the development of ion-based lithographic systems. This suite of ionbeam processing, modeling, and analysis techniques will be explored both from the perspective of the emerging science issues and from the technological challenges. copyright 1997 American Institute of Physics

The phase transition of an ionbeam into its crystalline state has long been expected to dramatically influence beam dynamics beyond the limitations of standard accelerator physics. Yet, although considerable improvement in beam cooling techniques has been made, strong heating mechanisms inherent to existing high-energy storage rings have prohibited the formation of the crystalline state in these machines up to now. Only recently, laser cooling of low-energy beams in the table-top rf quadrupole storage ring PAaul Laser cooLing Acceleration System (PALLAS) has lead to the experimental realization of crystalline beams. In this article, the quest for crystalline beams as well as their unique properties as experienced in PALLAS will be reviewed.

A major concern in the use of heavy ionbeams as igniters in pellet fusion systems is the vulnerability of the beam to the transverse flamentation instability. The undesirable consequence of this mode is the transverse heating of the beam to the extent that convergence on the pellet becomes impossible. This work considers the case of a beam injected into a gas filled reactor vessel, where finite pulse length and propagation distance play an important role in limiting growth. Two geometries are analyzed: a nonconverging case where the radius at injection is nearly equal to the desired radius at the pellet, and a converging case in which the injection radius is large and the beam is pre-focused to converge at the target. It is found that a cold beam will be severely disrupted if the product of the magnetic plasma frequency and the propagation distance is much larger than unity

The response of thin films of buckminsterfullerene (C 60 ) to energetic xenon ion impact is investigated. The diagnostics employed include Fourier Transform Infrared and Raman Spectroscopies, Cross-Sectional Transmission Electron Microscopy, and Atomic Force Microscopy. By combining the information obtained from these diagnostics with that from the dependence of the conductivity on ion dose, it is concluded that each C 60 molecule completely disintegrates when hit by an energetic ion. The cross-section for the destruction of about 7 x 10 -13 cm 2 for irradiation with 620 keV Xe ions. The disintegration occurs when C atoms are knocked-out of the molecule either directly by the impinging ion or by an energetic knock-on C atom with the damage cascade. This process is quite different from the Coulomb Explosion mechanism previously proposed in the literature. For very low ions doses ( 11 Xe/cm 2 ) most of the C 60 molecules remain intact; however this dose is sufficient to completely disrupt the ordering of the C 60 molecules in the van der Waals bonded C 60 solid. Disruption of the lattice ordering at such low doses is considered to be attributable to the weakness of the van der Waals forces which bind the C 60 clusters together into the molecular solid. 13 refs., 7 figs

PBFA II is a 100 TW pulsed power accelerator constructed at Sandia National Laboratories for use in the Light Ion Fusion Program. The objective of PBFA II is to accelerate and focus upon an inertial confinement fusion (ICF) target a lithium beam with sufficient energy, power, and power density to perform ignition scaling experiments. The technologies used in PBFA II include: (1) primary energy storage and compression with 6 MV, low-inductance Marx generators, (2) pulse forming in water-insulated, water-dielectric lines with self-closing water switches, (4) voltage addition in vacuum using self-magnetically-insulated biconic transmission lines, (5) inductive energy storage and pulse compression using a fast-opening plasma erosion switch, (6) beam formation using a magnetically-insulated ion diode, and (7) space-charge and current-neutralized beam propagation to the target in a gas-filled cell. The first multimodule shot was on December 11, 1985. The plans for PBFA II include development and demonstration of the pulse-shaping techniques which are necessary for high-gain target compressions. Following a modification of the accelerator which will probably include an ''extraction'' ion diode, a 4- to 5-meter plasma channel for beam bunching during propagation, and a target chamber located beneath the accelerator, temporally-shaped ionbeam pulses will be available for pulse-shaped target experiments. (author)

The aim of this work is to study the expansion in vacuum, of a positive ionbeam with the use of one dimensional (1D) analytic model and a two dimensional Particle-In-Cell (2D-PIC) simulation. The ionbeam is extracted and accelerated from preformed plasma by an extraction system composed of two polarized parallel perforated grids. The results obtained with both approaches reveal the presence of a potential barrier downstream the extraction system which tends to reflect the ion flux. The dependence of the critical distance for which all extractedions are reflected, is investigated as a function of the extractedionbeam current density. In particular, it is shown that the 1D model recovers the well-known Child-Langmuir law and that the 2D simulation presents a significant discrepancy with respect to the 1D prediction. Indeed, for a given value of current density, the transverse effects lead to a greater critical distance.

Thin films of bio-inert (TiO 2+α , Al 2 O 3+α ) and bio-active (compounds of calcium and phosphorus oxides, hydroxy-apatite) were deposited on the most commonly used implant materials such as titanium and stainless steel, using a dual-ion-beam deposition system. Rutherford backscattering spectroscopy was carried out for quantitative measurement of the interfacial atomic mixing and the composition of the elements. The experimental results show that by controlling the ionbeam energy and current, thin films with very good mechanical properties are obtained as a result of the ionbeam mixing within the film and at the interface of the film and substrate. (orig.)

This paper introduces a new scheme of ionbeam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ionbeam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ionbeam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

We have developed a high current metal ion implantation facility with which high current beams of virtually all the solid metals of the Periodic Table can be produced. The facility makes use of a metal vapor vacuum arc ion source which is operated in a pulsed mode, with pulse width 0.25 ms and repetition rate up to 100 pps. Beamextraction voltage is up to 100 kV, corresponding to an ion energy of up to several hundred keV because of the ion charge state multiplicity; beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Implantation is done in a broad-beam mode, with a direct line-of-sight from ion source to target. Here we describe the facility and some of the implants that have been carried out using it, including the 'seeding' of silicon wafers prior to CVD with titanium, palladium or tungsten, the formation of buried iridium silicide layers, and actinide (uranium and thorium) doping of III-V compounds. 16 refs., 6 figs

The mega-ampere currents associated with light ion fusion (LIF) require excellent charge neutralization to prevent divergence growth. As the size and space-charge potential of a beam clump or `beamlet` become small (submillimeter size and kilovolt potentials), the neutralization becomes increasingly difficult. Linear theory predicts that plasma electrons cannot neutralize potentials < {phi}{sub crit} = (1/2)m{sub e}v{sub i}{sup 2}/e, where m{sub e} is the electron mass and v{sub i} is the ionbeam velocity. A non-uniform beam would, therefore, have regions with potentials sufficient to add divergence to beam clumps. The neutralization of small beamlets produced on the SABLE accelerator and in numerical simulation has supported the theory, showing a plateau in divergence growths as the potential in the beamlet exceeds {phi}{sub crit}. (author). 1 tab., 2 figs., 4 refs.

The angle of ion incidence at the etched wafer location during RIBE and IBE using Cl 2 , Ar and O 2 ionbeams has been characterized using an ion energy and angle analyzer. Effects of beam current and accelerator grid bias on beam divergence and the spatial uniformity of the spread of incident angles are measured. It is observed that increased total beam current can lead to reduced current density at the sample stage due to enhanced beam divergence at high currents. Results are related to preferred etch system design for uniform high-aspect-ratio etching across semiconductor wafers

Ion storage in relativistic electron beams was calculated taking account of ion-ion charge exchange and ionization. The calculations were made for nitrogen ion storage from residual gas during the compression of electron rings in the adhezator of the JINR heavy ion accelerator. The calculations were made for rings of various parameters and for various pressures of the residual gas. The results are compared with analogous calculations made without account of ion-ion processes. It is shown that at heavy loading of a ring by ionsion-ion collisions play a significant part, and they should be taken into account while calculating ion storage

The design of the active cooling type ionbeam dump for JT-60 NBI which receives the total beam power of 5.6 MW for 10 sec continuously is described. It is composed of array of many finned tubes which is made of oxygen free copper with 0.2% silver content. The safety margin against thermal and mechanical troubles is estimated by the heat transfer and the thermal stress calculation. (author)

An ionbeam pulse radiolysis system has been constructed at HIMAC facility. Ionbeam of 24MeV He{sup 2+} with the duration longer than 1 {mu}s is available for irradiation. Three kinds of aqueous solutions, (C{sub 6}H{sub 5}){sub 2}CO, NaHCO{sub 3}, and KSCN, were irradiated and the absorption signals corresponding to (C{sub 6}H{sub 5}){sub 2}CO{sup -}, CO{sub 3}{sup -}, and (SCN){sub 2}{sup -} respectively were observed. Ghost signals which interfere with the measurement are also discussed. (author)

In the study of the effects of ionbeam irradiation of polymers very large doses can be administered in short times. Thousands of MGy can be produced in a small volume of a sample in a few minutes by bombarding with typical ionbeam currents. For instance, in an experiment done to observe the effects of 750 keV proton irradiation PVC, using a collimator of 1 mm diameter, 1 μC of charge integration deposits a dose of 50 MGy. The use of ionbeams also opens up the possibility of using the same beam for irradiation and for analysis of the effects, using the well known ionbeam analysis techniques. PIXE allows the measurement of chlorine in PVC. Polymers containing fluorine can be measured with the resonant nuclear reaction (RNR) technique, which is specific only to certain elements. The amount of hydrogen in the sample and its profile can be obtained using energy recoil detection analysis (ERDA); carbon, oxygen, and nitrogen can be measured and profiled using Rutherford backscattering (RBS) and also using the (d,p) and (d, α) nuclear reactions (NR). Loss of mass is one effect that can be studied using these techniques. It was studied in two different polymers, PVC and CR-39, in order to determine carbon buildup during ion irradiation. It was concluded that carbon builds up following different mechanisms in these two materials, due to the different possibilities of forming volatile compounds. It is also suggested that CR-39 should be a good material for ionbeam lithography. (author)

The state of research on intense ionbeam acceleration and transport is reviewed. The limitations imposed on ionbeam transport by space charge effects and methods available for neutralization are summarized. The general problem of ionbeam neutralization in regions free of applied electric fields is treated. The physics of acceleration gaps is described. Finally, experiments on multi-stage ion acceleration are summarized.

The state of research on intense ionbeam acceleration and transport is reviewed. The limitations imposed on ionbeam transport by space charge effects and methods available for neutralization are summarized. The general problem of ionbeam neutralization in regions free of applied electric fields is treated. The physics of acceleration gaps is described. Finally, experiments on multi-stage ion acceleration are summarized

The radioactive ionbeam (RIB) project at the Holifield Heavy Ion Research Facility (HHIRF) will provide for reconfiguration of the HHIRF accelerator system to enable provision of low-intensity RIBs for nuclear and astrophysics research. As we have progressed with the design of the reconfiguration, we have encountered several challenges that were not immediately obvious when first contemplating the project. The challenges do not seem insurmountable but should keep life interesting for those of us doing the work. A brief review of the project will allow a better understanding of the challenges in RIB production. Radioactive ionbeams will be produced with the Isotope Separator On-Line (ISOL) postacceleration technique. In particular, radioactive atoms will be produced by reactions in the thick stopping target of an ISOL-type target-ion source assembly using intense beams from the Oak Ridge Isochronous Cyclotron equipped with a light-ion internal source. This ISOL target-ion source assembly will be mounted on a high-voltage platform with a mass separator. The target ion source will operate at potentials up to 50 kV with respect to the high voltage platform. The radioactive atoms produced by nuclear reactions in the target diffuse to the surface of the heated target material, desorb from this surface, and effuse through a heated transfer tube into an ion source where ionization and extraction take place. Two types of ion sources will be initially considered. A Forced Electron Beam Induced Arc Discharge source, similar to those used by the ISOLDE facility at CERN and by the UNISOR facility at ORNL, will be built to produce positive ions. These positive ions will be focused through an alkali vapor charge-exchange canal to produce negative ions for tandem injection. In addition, a direct negative surface ionization addition or modification to the above source will be built and investigated

At Nuclear Science Centre (NSC), New Delhi, we have implemented a facility to produce low energy light radioactive ionbeams (RIBs) using (p,n) type of reactions in inverse kinematics. For this purpose primary beams from the 15-UD Pelletron accelerator impinged on a thin polypropylene foil mounted on a rotating/linearly moving target assembly. For efficiently separating the secondary beam from primary beam, the existing recoil mass spectrometer (RMS) HIRA was operated with new ion optics. Suitable hardware modifications were also made. Using this facility, we have extracted a 7 Be beam of purity better than 99% and spot-size ∼4 mm in diameter. This 7 Be beam has been utilized in a variety of experiments in the energy range of 15-22 MeV. Typical beam parameters are: intensity 10 4 pps, angular spread ±30 mrad and energy spread ±0.5 MeV. Development of appropriate detector setup/target arrangement were also made to perform these experiments. In this paper, we describe the implementation of this project

The project started with the design of the broad beam RF ion source and the single gap accelerating column. The preliminary results of the source show that the ion current extracted from the source could reach 30 m A with extraction voltage = 2 kV. The beam uniformity was made by the use of multi apertures graphite cathode designed to make perveance matching to the normal Gaussian distribution of the ionbeam. The beam uniformity could reach 66% of the beam width of 6 cm. The design of the single gap accelerating column based on tracing of beam lines inside the accelerating gap and estimation of the minimum value of the electric field required to contain the beam against space charge expansion in order to achieve minimum beam emittance without aberrations. The preliminary results of the acceleration of the ionbeams up to 20 KeV show an increase of the extractedion current with increase of the extraction voltage. This increase is due to decrease of the angular divergence of the beam due to the effect of increasing the axial velocity component of the accelerated field. 9 figs.

Ions have higher linear energy transfer (LET) near the end of their range and lower LET away from the end of their range. Mixing radiations of different LET complicates treatment planning because radiation kills cells in two statistically independent ways. In some cases, cells are killed by a single-particle, which causes a linear decrease in log survival at low dosage. When the linear decrease is subtracted from the log survival curve, the remaining curve has zero slope at zero dosage. This curve is the log survival curve for cells that are killed only by two or more particles. These two mechanisms are statistically independent. To calculate survival, these two kinds of doses must be accumulated separately. The effect of each accumulated dosage must be read from its survival curve, and the logarithms of the two effects added to get the log survival. Treatment plans for doses of protons, He 3 ions, and He 4 ions suggest that these ions will be useful therapeutic modalities

Clearly detectable quantities of molecular fullerene (C 60 ), the most recently discovered allotrope of carbon, have been observed in graphite following irradiation with heavy projectile ions at energies of about 1 GeV using high pressure chromatography. Similar experiments using lower ion energies gave no corresponding signal, indicating an absence of fullerene. This clear difference suggests that there exists an energy threshold for fullerene genesis. Beginning with a microscopic description of deposition and transfer of energy from the ion to the target, a theoretical model is developed for interpretation of these and similar experiments. An important consequence is a description of the formation of large carbon clusters in the hot dense 'primeval soup' of single carbon atoms by means of random 'sticky' collisions. The ion energy threshold is seen as arising, physically, from a balance in the competition between the rate of primary energy deposition and the rate of system cooling. Rate equations for the basic clustering process allow calculations of the time-dependent number densities for the different carbon clusters produced. An important consequence of the theory is that it is established that the region for the specific phase transition from graphite to fullerene lies in the same pressure regime on the phase diagram as does the corresponding transition for graphite to diamond. (author)

The formation of biaxial texture in uniaxially textured Ni thin films via Ar-ion irradiation is reported. The ion-beam irradiation was not simultaneous with deposition. Instead, the ionbeam irradiates the uniaxially textured film surface with no impinging deposition flux, which differs from conventional ion-beam-assisted deposition. The uniaxial texture is established via a nonion beam process, with the in-plane texture imposed on the uniaxial film via ionbeam bombardment. Within this sequential ionbeam texturing method, grain alignment is driven by selective etching and grain overgrowth

To improve the H{sup −} ionbeam optics, it is necessary to understand the energy relaxation process of surface produced H{sup −} ions in the extraction region of Cs seeded H{sup −} ion sources. Coulomb collisions of charged particles have been introduced to the 2D3V-PIC (two dimension in real space and three dimension in velocity space particle-in-cell) model for the H{sup −} extraction by using the binary collision model. Due to Coulomb collision, the lower energy part of the ion energy distribution function of H{sup −} ions has been greatly increased. The mean kinetic energy of the surface produced H{sup −} ions has been reduced to 0.65 eV from 1.5 eV. It has been suggested that the beam optics of the extracted H{sup −} ionbeam is strongly affected by the energy relaxation process due to Coulomb collision.

A servo control system has been incorporated into the practical slow extraction system in order to stabilize the spill structure less than a few kHz. Frequency responses of the components of the servo-spill control system and the open-loop frequency response were measured. The beam transfer function of the slow extraction process was derived from the measured data and approximated using a simple function. This is utilized to improve the performance of the servo-loop. (author)

Electron Cyclotron Resonance (ECR) ion source development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECR ion sources. So far at cw mode operation, up to 300 eμA of O 7+ and 1.15 emA of O 6+ , more than 100 eμA of intermediate heavy ions for charge states up to Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , and tens of eμA of heavy ions with charge states to Kr 26+ , Xe 28+ , Au 35+ , Bi 34+ and U 34+ have been produced from ECR ion sources. At an intensity of at least 1 eμA, the maximum charge state available for the heavy ions are Xe 36+ , Au 46+ , Bi 47+ and U 48+ . An order of magnitude enhancement for fully stripped argon ions (I ≥ 60 enA) also has been achieved. This article will review the ECR ion source progress and discuss key requirement for ECR ion sources to produce the highly charged ionbeams

Ion energy of the beam formed by an ion source is proportional to extractor voltage and ion charge state. Increasing the voltage is difficult and costly for extraction voltage over 100 kV. Here we explore the possibility of increasing the charge states of metal ions to facilitate high-energy, broad beamion implantation at a moderate voltage level. Strategies to enhance the ion charge state include operating in the regimes of high-current vacuum sparks and short pulses. Using a time-of-flight technique we have measured charge states as high as 7+ (73 kA vacuum spark discharge) and 4+ (14 kA short pulse arc discharge), both for copper, with the mean ion charge states about 6.0 and 2.5, respectively. Pulsed discharges can conveniently be driven by a modified Marx generator, allowing operation of ''Magis'' with a single power supply (at ground potential) for both plasma production and ionextraction

The Korea Multipurpose Accelerator Complex (KOMAC) has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz RF power, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. A beamextraction experiment for the test stand was performed, and the beam current was measured using a faraday cup in the chamber. A beamextraction results for the RF ion source will be presented. Beamextraction from the RF ion source of the test stand is verified by measuring the beam current with a faraday cup in the chamber. Thus far NI Labview, PLC and faraday cup have been used to measure the beam current. The OPC server is useful for monitoring the PLC values. The average beam current of (a), (b) and (c) shown in figure 2 are 110.241µA, 105.8597µA and 103.5278µA respectively.

At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ionbeams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ionbeam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ionbeam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω 2 scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extractedionbeam transverse coupling issues will be discussed, and the test results of the both TE 01 and HE 11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ionbeams, such as 1.42 emA Ar 12+ , 0.92 emA Xe 27+ , and so on, will be presented

During this thesis, a scanning ionbeam monitor has been developed in order to measure on-line fluence spatial distributions. This monitor is composed of an ionization chamber, Hall Effect sensors and a scintillator. The ionization chamber set between the beam exit and the experiment measures the ion rate. The beam spot is localized thanks to the Hall Effect sensors set near the beam sweeping magnets. The scintillator is used with a photomultiplier tube to calibrate the ionization chamber and with an imaging device to calibrate the Hall Effect sensors. This monitor was developed to control the beam lines of a radiobiology dedicated experimentation room at GANIL. These experiments are held in the context of the research in hadron-therapy. As a matter of fact, this new cancer treatment technique is based on ion irradiations and therefore demands accurate knowledge about the relation between the dose deposit in biological samples and the induced effects. To be effective, these studies require an on-line control of the fluence. The monitor has been tested with different beams at GANIL. Fluence can be measured with a relative precision of ±4% for a dose rate ranging between 1 mGy/s and 2 Gy/s. Once permanently set on the beam lines dedicated to radiobiology at GANIL, this monitor will enable users to control the fluence spatial distribution for each irradiation. The scintillator and the imaging device are also used to control the position, the spot shape and the energy of different beams such as those used for hadron-therapy. (author)

Herbage seeds of legume and grass were irradiated in penetration by 80 MeV/u 20 Ne 10+ ions. The results of field tests and observations of the root-tip cells showed that growth of the seedling was obviously weakened with increasing doses. Frequencies of chromosomal aberration and micronucleus increased significantly with increasing doses. According to the field growth tests, radiation sensitivity of grass herbage to the heavy ionbeams was much higher than leguminous herbage, and suitable dose of the heavy ion irradiation for the grass and leguminous herbage is 20-30 Gy and 150 Gy, respectively

Fast (MeV) molecular-ionbeams provide a unique source of energetic projectile nuclei which are correlated in space and time. The recognition of this property has prompted several recent investigations of various aspects of the interactions of these ions with matter. High-resolution measurements on the fragments resulting from these interactions have already yielded a wealth of new information on such diverse topics as plasma oscillations in solids and stereochemical structures of molecular ions as well as a variety of atomic collision phenomena. The general features of several such experiments will be discussed and recent results will be presented

Over the last few years many ionbeam techniques have been reported for the profiling of hydrogen in materials. Nine of these were evaluated using similar samples of hydrogen ion-implanted into silicon. When possible the samples were analyzed using two or more techniques to confirm the ion-implanted accuracy. The results of this analysis which has produced a consensus profile of H in silicon which is useful as a calibration standard are reported. The analytical techniques used have capabilities ranging from very high depth resolution (approximately 50 A) and high sensitivity (less than 1 ppM) to deep probes for hydrogen which can sample throughout thin sheets

Results are given of an experimental study of beam focusing by aperture displacement (Δx) in duoPIGatron ion sources. Measurements with a single aperture, accel-decel electrode geometry show that the beam deflection angle is linear with Δx/z for the round aperture and with Δx/z* 2 for the slit aperture where z and z* are respectively the extraction gap distance and the effective gap distance. Applying the result of the single aperture study to the multiaperture, duoPIGatron sources, it was possible to increase the neutral beam injection power to the ORMAK plasma by approximately 40 percent. Also presented are discussion and comparison of other work on the effect of aperture displacement on beam deflection. (U.S.)

Complementing the diode and beam transport optimization studies currently performed at FZK Karlsruhe on the proton-beam-facility PROFA, supplementary investigations were run at the St. Petersburg State University, focusing on ionbeam divergence and composition measurements using the TOF techniques. To ensure direct transferability of the results to the PROFA facility, these measurements were made on a scaled-down replica of the PROFA diode, comprising an array of small polyethylene flash-over plasma sources and a grid extraction system. Only the results of the beam composition measurements are presented, and the following conclusions are made: (i) The ionbeam contains H and C ions and heavier constituents that remain to be identified. (ii) The beam composition changes significantly with the total number of shots: While H{sup +} ions predominated in the starting phase of the experiments, heavier components outweighed them later on, presumably due to hydrogen depletion of the surface layer of the anode polyethylene units. (iii) Reconditioning of the polyethylene units may be possible by running the diode at higher currents (self-cleaning) or by cutting off a surface layer. (author). 7 figs., 3 refs.

Recent work on enhanced interdiffusion rates during ion-beam mixing at elevated temperatures is reviewed. As discussed previously, expected increase in ion-beam mixing rates due to 'radiation-enhanced diffusion' (RED), i.e. the free migration of isolated vacancy and interstitial defects, is well documented in single-crystal specimens in the range of 0.4 to 0.6 of absolute melting temperature. In contrast, the increase often observed at somewhat lower temperatures during ion-beam mixing of polycrystalline specimens is not well understood. However, sufficient evidence is available to show that this increase reflects intracascade enhancement of a thermally-activated process that also occurs without irradiation. Recent evidence is presented which suggests that this process is Diffusion-induced Grain-Boundary Migration (DIGM). An important complementary conclusion is that because ion-beam mixing in single-crystal specimens exhibits no significant temperature dependence below that of RED, models that invoke only irradiation-specific phenomena, e.g., cascade-overlap, thermal-spikes, or liquid-diffusion, and hence which predict no difference in mixing behavior between single- or poly-crystalline specimens, cannot account for the existing results

Radioactive Ion (nuclear) Beams have become prolific recently. Nuclear physics and associated subjects have staged a comeback to almost the beginning with the advent of RIB. A dedicated National Centre for RIB (NCRIB) proposed, discussed at several forums and under serious consideration is described

BEARS (Berkeley Experiments with Accelerated Radioactive Species) is an initiative to develop a radioactive ion-beam capability at Lawrence Berkeley National Laboratory. The aim is to produce isotopes at an existing medical cyclotron and to accelerate them at the 88 inch Cyclotron. To overcome the 300-meter physical separation of these two accelerators, a carrier-gas transport system will be used. At the terminus of the capillary, the carrier gas will be separated and the isotopes will be injected into the 88 inch Cyclotron's Electron Cyclotron Resonance (ECR) ion source. The first radioactive beams to be developed will include 20-min 11 C and 70-sec 14 O, produced by (p,n) and (p,α) reactions on low-Z targets. A test program is currently being conducted at the 88 inch Cyclotron to develop the parts of the BEARS system. Preliminary results of these tests lead to projections of initial 11 C beams of up to 2.5 x 10 7 ions/sec and 14 O beams of 3 x 10 5 ions/sec

The special aspects of treatment planning for ionbeams are outlined in this chapter, starting with positioning and immobilization of the patient, describing imaging and segmentation, definition of treatment parameters, dose calculation and optimization, and, finally, plan assessment, verification, and quality assurance.

Electron cloud (EC) driven instability can cause beam loss, emittance growth, trajectory change and wake fields. Mentioned crucial effects of EC motivated researchers to understand the EC build up mechanism and the effects of EC to the beam. This motivation also induced the progress of developing new simulation codes. EC simulations can roughly be divided into two classes such as, softwares whose goals are to simulate the build up of the EC during the passage of a bunch train and the codes which model the interaction of a bunch with an EC. The aim of this study is to simulate the effects of electron cloud (EC) on the dynamics of heavy ionbeams which are used in heavy ion synchrotron (SIS-18) at GSI. To do this, a 3-D and self-consistent simulation program based on particle in cell (PIC) method is used. In the PIC cycle, accurate solution of the Maxwell equations is obtained by employing discontinuous Galerkin finite element method. As a model, we assumed a perfectly conducting beam pipe which was uniformly (or randomly) loaded with the electrons. Then as parallel with the realistic cases in SIS-18, a single bunch consisting of U{sup +73} ions was extracted which could propagate in this pipe. Due to EC-ion bunch interaction, electrons gained energy and their displacements were observed. Electric and magnetic field components and EC charge density were calculated, numerically.

The SIBC (Surrey IonBeam Centre) is an element of the Virtual IonBeam Centre that coordinates 3 U.K. experimental facilities: SIBC (University of Surrey) for implantation and ionbeam applications, Miami and MEIS facility (University of Huddersfield) and gamma ray and neutron irradiation emulation facility (University of Manchester). The SIBC works actively with industry, developing bespoke processes and services, particularly for the photonics industry and provides ionbeam facilities to about 20 companies across the world. It operates a stringent quality control program and is one of the few ionbeam laboratories in the world to operate under ISO 9001 certification. The equipment of SIBC is presented and some applications of ionbeam analysis concerning the identification of gunshot residues, the determination of the origin of a painting, the analysis of proteins are described. Different techniques such as PIXE (Particle Induced X-ray Emission), RBS (Rutherford Backscattering Spectroscopy), NRA (Nuclear Reaction Analysis), SIMS (Secondary Ion Mass Spectrometry) are also explained in the slides of the presentation that have been added at the end of the paper

The present paper discusses some key or candidate techniques for future ion source development and such ion sources developed by the author. Several types of microwave ion sources for producing low charge state ions have been developed in Japan. When a microwave plasma cathode developed by the author is adapted to a Kaufman type ion source, the electron emission currents are found to be 2.5 A for argon gas and 0.5-0.9 A for oxygen gas. An alternative ionization method for metal atoms is strongly required for high-speed processing of material surface by metal-ionbeams. Detailed discussion is made of collisional ionization of vaporized atoms, and negative-ion production (secondary negative-ion emission by sputtering). An impregnated electrode type liquid-metal ion source developed by the author, which has a porous tip structure, is described. The negative-ion production efficiency is quite high. The report also presents a neutral and ionized alkaline-metal bombardment type heavy negative-ion source, which consists of a cesium plasma ion source, suppressor, target electrode, negative-ionextraction electrode, and einzel lens. (N.K.)

In order to study beam optics of NIRS-ECR ion source used in the HIMAC project, the EGUN code has been modified to make it capable of modeling ionextraction from a plasma. Two versions of the modified code are worked out with two different methods in which 1D and 2D sheath theories are used, respectively. Convergence problem of the strong nonlinear self-consistent equations is investigated. Simulations on NIRS-ECR ion source and HYPER-ECR ion source are presented in this paper, exhibiting an agreement with the experiment results.

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ionbeam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ionbeam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs.

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ionbeam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs.

A heavy ionbeam probe has been used to measure the radial space potential distribution in the central cell of TMX. This was the first beam probe system to utilize computer control, CAMAC instrumentation, and fast time response for broadband fluctuation capabilities. The fast time response was obtained using off-line processing of the energy analyzer detector signals and wideband transimpedance amplifiers. The on-axis space potential was found to be 300--400 V, with φ e /T ec ∼8. The radial potential profile is parabolic when gas box fueling is used. The frequency of observed fluctuations was found to agree with the E x B plasma rotation frequency during the discharge. The measured Tl ++ secondary ion current level is consistent with calculations, given reasonable assumptions for beam attenuation

The stability limits of the ion‐beam‐excited, electrostatic, ion cyclotron instability were investigated in a Q‐machine plasma where the electrons could be heated by microwaves. In agreement with theory, the beam energy necessary for excitation decreased with increasing electron temperature....

The stability limits of the ion‐beam‐excited, electrostatic, ion cyclotron instability were investigated in a Q‐machine plasma where the electrons could be heated by microwaves. In agreement with theory, the beam energy necessary for excitation decreased with increasing electron temperature....

In this study, I have tried to provide a better understanding of the dynamics of ions inside an electrostatic ionbeam trap. The electrostatic ion trap allows to store ions moving between two electrostatic mirrors. Although the trap has been developed already seven years ago, no direct measurement of the transversal velocity distribution of the ions has been performed. Such quantity is central for understanding the conditions under which a beam should be produced (mainly emittance) in order to be trapped by such a device. The data I have obtained during the course of this work are based on an experimental technique which relies on the direct imaging of the particles exiting the trap, as well as on numerical simulations of the ion trajectories inside the trap. I have personally been involved in the hardware development of the imaging system, the data acquisition and analysis of the data as well as il all numerical calculations presented here. These results allow us to obtain, for the first time, experimental information on the transverse phase space of the trap, and contribute to the overall understanding of the ion motion in this system. (author)

The clinical operation at the Heidelberg IonBeam Therapy Center (HIT) started in November 2009; since then more than 1600 patients have been treated. In a 24/7 operation scheme two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce protons and carbon ions. The modification of the low energy beam transport line and the integration of a third ion source into the therapy facility will be shown. In the last year we implemented a new extraction system at all three sources to enhance the lifetime of extraction parts and reduce preventive and corrective maintenance. The new four-electrode-design provides electron suppression as well as lower beam emittance. Unwanted beam sputtering effects which typically lead to contamination of the insulator ceramics and subsequent high-voltage break-downs are minimized by the beam guidance of the new extraction system. By this measure the service interval can be increased significantly. As a side effect, the beam emittance can be reduced allowing a less challenging working point for the ion sources without reducing the effective beam performance. This paper gives also an outlook to further enhancements at the HIT ion source testbench.

The results of the research concerning the extraction system of the fast electrons from a cold cathode high voltage glow discharge plasma electron source (HVPES) are presented. For using the electron beam in a more flexible way, that is changing the shape of the minimum cross-section, (or beam cross-over), of the beam in a sample S frontal plane, without perturbing the discharge parameters, some modifications to a reference internal geometry were tested. Finally, a geometry was found in which the discharge volume may be separated in two parts, one, `a discharge space`, filled with plasma and fast electrons and another, `working space`, occupied specially by the fast electron beam. In this new geometry the electrical discharge parameters, I{sub d} - discharge current, U{sub d} - discharge voltage, were the same as for the reference geometry. (authors) 5 refs., 4 figs., 3 tabs.

The results of the research concerning the extraction system of the fast electrons from a cold cathode high voltage glow discharge plasma electron source (HVPES) are presented. For using the electron beam in a more flexible way, that is changing the shape of the minimum cross-section, (or beam cross-over), of the beam in a sample S frontal plane, without perturbing the discharge parameters, some modifications to a reference internal geometry were tested. Finally, a geometry was found in which the discharge volume may be separated in two parts, one, 'a discharge space', filled with plasma and fast electrons and another, 'working space', occupied specially by the fast electron beam. In this new geometry the electrical discharge parameters, I d - discharge current, U d - discharge voltage, were the same as for the reference geometry. (authors)

To achieve the heavy ion radiotherapy more precisely, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. From a heavy ion CT image, we can directly obtain the 2-D distribution of the electron density in a sample. For this purpose, we have developed a broad beam heavy ion CT system. The electron density was obtained using some kinds of solutions targets. Also the dependence of the spatial resolution on the target size and the kinds of beams was estimated in this work using cylinders targets of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. (author)

Target design for Heavy IonBeam Fusion and related physics are discussed. First, a modified version of the Kidder-Bodner model for pellet gain is presented and is used to define the working point (Esub(beam) = 4.8 MJ, Gain 83) for a reactor size target. Secondly, stopping of heavy ions in hot dense plasma is investigated and numerical results for stopping powers and ranges of 10 GeV Bi-ions in Pb, Li, and PbLi-alloy are given. Finally, results of an explicit implosion calculation, using the 1-D code MINIHY, are discussed in detail. The hydrodynamic efficiency is found to be about 5%. Special attention is given to the shock sequence leading to the ignition configuration. Also the growth of Rayleigh-Taylor instability at the absorber-pusher interface is estimated. (orig.)

For the on-line production of a 14 O + ionbeam, an integrated target--transfer line ion source system is now under development at LBNL. 14 O is produced in the form of CO in a high temperature carbon target using a 20 MeV 3 He beam from the LBNL 88'' Cyclotron via the reaction 12 C( 3 He,n) 14 O. The neutral radioactive CO molecules diffuse through an 8 m room temperature stainless steel line from the target chamber into a cusp ion source. The molecules are dissociated, ionized and extracted at energies of 20 to 30 keV and mass separated with a double focusing bending magnet. The different components of the setup are described. The release and transport efficiency for the CO molecules from the target through the transfer line was measured for various target temperatures. The ionbeam transport efficiencies and the off-line ion source efficiencies for Ar, O 2 and CO are presented. Ionization efficiencies of 28% for Ar + , 1% for CO, 0.7% for O + , 0.33 for C + have been measured

Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored

A wide range of research and development activities of advanced material synthesis using ionbeams will be discussed, including ionbeam applications to the state-of-the-art electronics from giant to nano electronics. (author)

Linac4 is a part of the upgrade of CERN’s accelerator complex for increased luminosity in the LHC. A new system to extract the ionbeam from the plasma generator has been designed and tested, in order to improve the reliability and beam optics of the pulsed H- ion source. This paper presents the successfully implemented extraction system and three different beam measurements. The simulations compare well to the measurements and show that the plasma density was too low for the extraction system design during the measurements.

Complete text of publication follows. The characteristics features of the formation of the spatial distribution of the energy transferred to the plasma from a beam of ions with different initial energies, masses and charges under fast ignition conditions are determined. The motion of the Bragg peak is extended with respect to the spatial distribution of the temperature of the ion-beam-heated medium. The parameters of the ionbeams are determined to initiate different regimes of fast ignition of thermonuclear fuel precompressed to a density of 300-500 g/cm 3 - the edge regime, in which the ignition region is formed at the outer boundary of the fuel, and the internal regime, in which the ignition region is formed in central parts of the fuel. The conclusion on the requirements for fast ignition by light and heavy ionbeams is presented. It is shown that the edge heating with negative temperature gradient is described by a self-similar solution. Such a temperature distribution is the reason of the fact that the ignited beam energy at the edge heating is larger than the minimal ignition energy by factor 1.65. The temperature Bragg peak may be produced by ionbeam heating in the reactor scale targets with pR-parameter larger than 3-4 g/cm 2 . In particular, for central ignition of the targets with pR-parameters in the range of 4-8 g/cm 2 the ionbeam energy should be, respectively, from 5 to 7 times larger than the minimal ignition energy. The work by S.Ye. Gus'kov, D.V. Il'in, and V.E. Sherman was supported by the Ministry of Education and Science of the Russian Federation under the program 'Development of the Scientific Potential of High Education for 2009-2010' (project no. 2.1.1/1505) and the Russian Foundation for Basic Research (project no. 08-02-01394 a ). The work by J. Limpouch and O. Klimo was supported by the Czech Ministry of Education (project no. LC528, MSM6840770022).

It is desired to consider the problem of current neutralization of heavy ionbeams traversing gas backgrounds in which the conductivity changes due to beam heating and beam convergence. The procedure is to determine Green's-function solutions to the magnetic-diffusion equation derived from Maxwell's equations and an assumed scaler-plasma conductivity sigma for the background-electron current density j/sub e/. The present calculation is more general than some previously carried out in that arbitrary time variations for the beam current j/sub b/ and conductivity are allowed and the calculation is valid for both weak and strong neutralization. Results presented here must be combined with an appropriate energy-balance equation for the heated background in order to obtain the neutralization self-consistently

DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ionbeam biotechnology and ionbeam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ionbeam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ionbeam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli ( E. coli) for mutation analysis indicated that the charged ionbeam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ionbeam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ionbeam biotechnology and ionbeam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ionbeam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ionbeam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli (E. coli) for mutation analysis indicated that the charged ionbeam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ionbeam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

A workshop on applications of ionbeam analysis was held at ANSTO, immediate prior to the IBMM-95 Conference in Canberra. It aims was to review developments and current status on use of ionbeams for analysis, emphasizing the following aspects: fundamental ionbeam research and secondary effects of ionbeams; material sciences, geological, life sciences, environmental and industrial applications; computing codes for use in accelerator research; high energy heavy ion scattering and recoil; recent technological development using ionbeams. The handbook contains the workshop's program, 29 abstracts and a list of participants

Briefly, the paper provides some basic information on the use of ionbeams for surface alloying and surface analysis. After a brief historical review of those fields in which the techniques are already widely applied the important features of typical ionbeam machines are described. The basic processes that occur when an ionbeam strikes a solid are then considered. Selected ionbeam analysis techniques are then discussed. Attention is drawn, wherever possible, to applications in corrosion science and engineering. (author)

Cardiovascular disease is one of the leading causes of the death in the USA and developed countries. More than 570,000 artery bypass graft surgeries per USA are performed each year, though percutaneous devices have abounded in extreme cases. Based on the surgery follow-ups, large diameter expanded polytetrafluoroethylene (ePTFE) (>5 mm) are clinically employed with good results but its clinical applications in smaller vessels is still problematic due to thrombosis and neointima formation. Achievement of high patency grafts has been to some extent achieved by numerous methods of surface modification techniques, but its results are less than its initial hopes. As examples, endothelial cells coated on the luminal surface of ePTFE has demonstrated limited success after recirculation. Surface modifications of PTFE film with either argon ionbeam or UV light from Xe-excimer lamp were reported to increase its interaction with vascular endothelial cell. Surface modification of poly(lactide-co-glycolide)[PLGA] is also very important in tissue engineering, in where induction of its initial high cellular adhesion and spreading is a critical step for development of tissue engineering medical products. We previously reported tissue engineering of the hybrid ePTFE scaffold by seeding smooth muscle cells and subsequently evaluation of its tissue regeneration behaviors and stabilities with circulation of pulsatile flow. To improve its tissue engineering more quickly, we here performed surface modification of ePTFE and porous PLGA scaffold and evaluated its subsequent chemical and biological properties after treating its surface with low energy ionbeams. The porous ePTFE was prepared in a round shape (diameter = 1 cm) and dried after organic solvent extraction for ionbeam treatment. Another porous PLGA layers (d = 1 cm, t = 1 cm with approximately 92% porosity) were fabricated and treated its surface by irradiating low energy either nitrogen or argon ionbeams (1 keV, 1x1015 ions

Cardiovascular disease is one of the leading causes of the death in the USA and developed countries. More than 570,000 artery bypass graft surgeries per USA are performed each year, though percutaneous devices have abounded in extreme cases. Based on the surgery follow-ups, large diameter expanded polytetrafluoroethylene (ePTFE) (>5 mm) are clinically employed with good results but its clinical applications in smaller vessels is still problematic due to thrombosis and neointima formation. Achievement of high patency grafts has been to some extent achieved by numerous methods of surface modification techniques, but its results are less than its initial hopes. As examples, endothelial cells coated on the luminal surface of ePTFE has demonstrated limited success after recirculation. Surface modifications of PTFE film with either argon ionbeam or UV light from Xe-excimer lamp were reported to increase its interaction with vascular endothelial cell. Surface modification of poly(lactide-co-glycolide)[PLGA] is also very important in tissue engineering, in where induction of its initial high cellular adhesion and spreading is a critical step for development of tissue engineering medical products. We previously reported tissue engineering of the hybrid ePTFE scaffold by seeding smooth muscle cells and subsequently evaluation of its tissue regeneration behaviors and stabilities with circulation of pulsatile flow. To improve its tissue engineering more quickly, we here performed surface modification of ePTFE and porous PLGA scaffold and evaluated its subsequent chemical and biological properties after treating its surface with low energy ionbeams. The porous ePTFE was prepared in a round shape (diameter = 1 cm) and dried after organic solvent extraction for ionbeam treatment. Another porous PLGA layers (d = 1 cm, t = 1 cm with approximately 92% porosity) were fabricated and treated its surface by irradiating low energy either nitrogen or argon ionbeams (1 keV, 1x1015 ions

In an axisymmetric plasma, the conservation of canonical angular momentum constrains heavy ionbeam probe (HIBP) trajectories such that measurement of the toroidal velocity component of secondary ions provides a localized determination of the poloidal flux at the volume where they originated. We have developed a prototype detector which is designed to determine the beam angle in one dimension through the detection of ion current landing on two parallel planes of detecting elements. A set of apertures creates a pattern of ion current on wires in the first plane and solid metal plates behind them; the relative amounts detected by the wires and plates determine the angle which beamions enter the detector, which is used to infer the toroidal velocity component. The design evolved from a series of simulations within which we modeled ionbeam velocity changes due to equilibrium and fluctuating magnetic fields, along with the ionbeam profile and velocity dispersion, and studied how these and characteristics such as the size, cross section, and spacing of the detector elements affect performance.

In an axisymmetric plasma, the conservation of canonical angular momentum constrains heavy ionbeam probe (HIBP) trajectories such that measurement of the toroidal velocity component of secondary ions provides a localized determination of the poloidal flux at the volume where they originated. We have developed a prototype detector which is designed to determine the beam angle in one dimension through the detection of ion current landing on two parallel planes of detecting elements. A set of apertures creates a pattern of ion current on wires in the first plane and solid metal plates behind them; the relative amounts detected by the wires and plates determine the angle which beamions enter the detector, which is used to infer the toroidal velocity component. The design evolved from a series of simulations within which we modeled ionbeam velocity changes due to equilibrium and fluctuating magnetic fields, along with the ionbeam profile and velocity dispersion, and studied how these and characteristics such as the size, cross section, and spacing of the detector elements affect performance.

The Particle Beam Fusion Accelerator II (PBFA II) is presently under construction and is the only existing facility with the potential of igniting thermonuclear fuel in the laboratory. The accelerator will generate up to 5 megamperes of lithium ions at 30 million electron volts and will focus them onto an inertial confinement fusion (ICF) target after beam production and focusing have been optimized. Since its inception, the light ion approach to ICF has been considered the one that combines low cost, high risk, and high payoff. The beams are of such high density that their self-generated electric and magnetic fields were thought to prohibit high focal intensities. Recent advances in beam production and focusing demonstrate that these self-forces can be controlled to the degree required for ignition, break-even, and high gain experiments. ICF has been pursued primarily for its potential military applications. However, the high efficiency and cost-effectiveness of the light ion approach enhance its potential for commercial energy application as well

Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ionbeam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ionbeam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ionbeam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

Detailed studies of recombination processes between electrons and highly charged ions have become possible by recent improvements of merged-beams experiments. We discuss in particular measurements with stored cooled ionbeams at the Test Storage Ring (TSR) in Heidelberg. The cross section of dielectronic recombination was measured with high energy resolution for few-electron systems up to the nuclear charge of Cu at a relative energy up to 2.6 keV. At low energy (∼0.1 eV) total recombination rates of several ions were measured and compared with calculated radiative recombination rates. Laser-stimulated recombination of protons and of C 6+ ions was investigated as a function of the photon energy using visible radiation. Both the total recombination rates and the stimulated recombination spectra indicate that in spite of the short interaction time in merged beams, also collisional capture of electrons into weakly bound levels (related to three-body recombination) could be important

The underlying principle of inertial confinement is the irradiation of a small pellet filled with DT-fuel by laser or particle beams in order to compress the fuel and ignite it. As 'drivers' for this process large laser installations and light-ion devices have been built since then and the results obtained during the past few years have increased our confidence, that the ignition conditions might be reached. Further conditions, however, have to be fulfilled for operating a power plant. In particular, the driver needs to have enough efficiency to be economical, and for a continuous energy production a high repetition rate and availability is required. It is less than ten years since it was realized that heavy ionbeams might be a promising candidate for achieving inertial confinement fusion (ICF). Due to the evolution of high-energy and heavy-ion physics during the past 25 years, accelerators have attained a high technical and technological standard and an excellent operational reliability. Nevertheless, the heavy ion driver for a fusion power plant requires beam specifications exceeding those of existing accelerators considerably. (Auth.)

During substorms the short beams of ions in the keV-to-tens keV energy range are injected into the auroral flux tubes from the magnetotail (sometimes extending up to >100 keV energy) carrying the information on the source distance, scale-size and temporal history of plasma acceleration. We present observations with the CLUSTER crossing inward the auroral zone flux tubes at ~4Re distance near its perigee during the substorm activity on February 14, 2001. The ionbeams cover the same region (poleward half) of the auroral oval where the low-energy ions are extracted from the ionosphere, and where the small-scale transient transverse Alfven waves are observed which carry predominantly the downward parallel Poynting flux into the ionosphere. The multiple beams were basically confirmed to be the transient effects, although some effects including the (spatial) velocity filter and the parallel electric fields (im- posed by quasineutrality requirement) may complicate the interpretation. The gener- ation region of ionbeams is not limited to most poleward, newly-reconnected flux tubes; the beam generation region could extend across magnetic field inward by as much as >100km (if mapped to the ionosphere). Surprising variety of injection dis- tances observed nearly simultaneously (ranging between >60 Re and ~10 Re) have been inferred when using the full available energy and time resolution, with shorter injection distances be possibly associated with the flow braking process. The beam multiplicity often displays the apparent ~3 min quasiperiodicity inherent to the basic dissipation process, it was not yet explained by any substorm theory.

Since the mid of 1980's, ionbeam had been widely used in mutagenic breeding of various crops. Ionbeam biotechnology had provided a new way for improving corn variety and creating new germplasm resources, and had promoted the development of maize breeding. The ionbeam characteristics, the mutagenic mechanism and its application in maize breeding were described. (authors)

One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ionbeams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ionbeamextraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

Silicon lenses are widely used for infrared applications. Especially for portable devices the size and weight of the optical system are very important factors. The use of aspherical silicon lenses instead of spherical silicon lenses results in a significant reduction of weight and size. The manufacture of silicon lenses is more challenging than the manufacture of standard glass lenses. Typically conventional methods like diamond turning, grinding and polishing are used. However, due to the high hardness of silicon, diamond turning is very difficult and requires a lot of experience. To achieve surfaces of a high quality a polishing step is mandatory within the manufacturing process. Nevertheless, the required surface form accuracy cannot be achieved through the use of conventional polishing methods because of the unpredictable behavior of the polishing tools, which leads to an unstable removal rate. To overcome these disadvantages a method called IonBeam Figuring can be used to manufacture silicon lenses with high surface form accuracies. The general advantage of the IonBeam Figuring technology is a contactless polishing process without any aging effects of the tool. Due to this an excellent stability of the removal rate without any mechanical surface damage is achieved. The related physical process - called sputtering - can be applied to any material and is therefore also applicable to materials of high hardness like Silicon (SiC, WC). The process is realized through the commercially available ionbeam figuring system IonScan 3D. During the process, the substrate is moved in front of a focused broad ionbeam. The local milling rate is controlled via a modulated velocity profile, which is calculated specifically for each surface topology in order to mill the material at the associated positions to the target geometry. The authors will present aspherical silicon lenses with very high surface form accuracies compared to conventionally manufactured lenses.

The workshop that generated this data was convened to develop a set of recommendations (a priority list) for possible funding in the area of US domestic ionbeam irradiation capabilities for nuclear energy-focused RD&D. The results of this workshop were intended for use by the Department of Energy - Office of Nuclear Energy (DOE-NE) for consideration of support for these facilities. The workshop considered, as part of the initial potential future support discussions, input submitted through the Office of Nuclear Energy Request for Information (RFI) (DE-SOL-0008318, April 13, 2015), but welcomed discussion (and presentation) of other options, whether specific or general in scope. Input from users, including DOE-NE program interests and needs for ion irradiation RD&D were also included. Participants were selected from various sources: RFI respondents, NEUP/NEET infrastructure applicants, universities with known expertise in nuclear engineering and materials science and other developed sources. During the three days from March 22-24, 2016, the workshop was held at the Idaho National Laboratory Meeting Center in the Energy Innovation Laboratory at 775 University Drive, Idaho Falls, ID 83401. Thirty-one members of the ionbeam community attended the workshop, including 15 ionbeam facilities, six representatives of Office of Nuclear Energy R&D programs, an industry representative from EPRI and the chairs of the NSUF User’s Organization and the NSUF Scientific Review Board. Another four ionbeam users were in attendance acting as advisors to the process, but did not participate in the options assessment. Three members of the sponsoring agency, the Office of Science and Technology Innovation (NE-4) also attended the workshop.

We studied the optical and thermal properties of aromatic polymer films which had been irradiated with 1 MeV H + , H 2 + and He + ions. The examined aromatic polymers were polyetherether ketone(PEEK), polyetherimide(PEI), polyether sulfon(PES), polysulfon(PSF), and polyphenylene sulfide(PPS). The optical densities at 300nm of PES and PSF greatly increased after the irradiation. The optical densities at 400nm of all the examined polymer lineally increased with the irradiation dose. The PEEK film which had been irradiated with 1 MeV H + was not deformed above melting point. This demonstrates that cross-linking occurs in PEEK films by ionbeam irradiation. As for the effects, depending on the mass of the irradiated ions, it was found that the ions with a high mass induced larger effects on the aromatic polymers for the same absorption energy. (author)

A meniscus of plasma-beam boundary in H{sup -} ion sources largely affects the extracted H{sup -} ionbeam optics. Although it is hypothesized that the shape of the meniscus is one of the main reasons for the beam halo observed in experiments, a physical mechanism of the beam halo formation is not yet fully understood. In this letter, it is first shown by the 2D particle in cell simulation that the H{sup -} ionsextracted from the periphery of the meniscus cause a beam halo since the surface produced H{sup -} ions penetrate into the bulk plasma, and, thus, the resultant meniscus has a relatively large curvature.

Analyses are given for structures of deflagration waves formed by ionbeams in spherical targets. The singularity at the sonic point disappears in the spherical target if the beam pressure is in balance with the plasma pressure. The expanding supersonic flow of the background plasma can be connected with the subsonic flow in the core of the target through the deflagration wave. The length and the strength of the deflagration wave in the spherical target is comparable with the corresponding ones in the slab target. (author)

In this paper we describe the structure and the composition of (Al,Ga)N/GaN Bragg reflectors obtained from Rutherford backscattering spectroscopy. Bragg reflectors constitute a part of blue (λ = 450 nm) resonant cavity light emitting diodes. To improve the measurement accuracy, three tilt angles have been used (10 deg. , 25 deg. and 50 deg. ). In a second part of the paper, ionbeam induced charges study has been carried out, with a 2 MeV 4 He + micro-beam, on metal-semiconductor-metal UV photodetectors. Results have been taken into account for the design of the photodetector electrodes

We have developed a new in situ observation system for dynamic processes under dual ionbeam irradiation. The system consists of a modified 400 keV analytical electron microscope (JEOL, JEM-4000FX) and two 40 kV ionbeam accelerators. This system allows evaluation of microscopic changes of structure and chemical bonding state of materials in the dynamic processes under two kinds of ionbeam irradiations, that is required for the simulation test of the first wall of nuclear fusion reactors onto which He + , H + , and H 2 + ions are irradiated simultaneously. These two ion accelerators were equipped symmetrically both sides of the electron microscope and individually controlled. Each ionbeamextracted from a duo-plasmatron ion gun is bent downward by an angle of 30deg with a mass-separating magnet, and introduced into specimen chamber of the electron microscope. Inside the specimen chamber the beam is deflected again by an angle of 30deg with an electrostatic prism so as to be incident on the specimen surface. Finally, two ionbeams from both side are incident on the specimen surface at an angle of 60deg. The maximum ion current density of helium is more than 250μA/cm 2 at the specimen at an ion energy of 17 keV. Images of the electron microscope during dual ionbeam irradiation are observed through a TV camera and recorded with a VTR. (author)

Brookhaven National Laboratory has developed the new preinjector system, electron beamion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ionbeam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved IonBeam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a -.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ionbeam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients

Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved IonBeam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a {minus}.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ionbeam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients.

Low-energy ionbeam biotechnology (IBBT) has recently been rapidly developed worldwide. Ion-beam-induced DNA transfer is one of the important applications of IBBT. However, mechanisms involved in this application are not yet well understood. In this study plasma-neutralized ionbeam was applied to investigate ion charge effect on induction of DNA transfer. Argon ionbeam at 7.5 keV was neutralized by RF-driven plasma in the beam path and then bombarded cellulose membranes which were used as the mimetic plant cell envelope. Electrical properties such as impedance and capacitance of the membranes were measured after the bombardment. An in vitro experiment on plasmid DNA transfer through the cellulose membrane was followed up. The results showed that the ion charge input played an important role in the impedance and capacitance changes which would affect DNA transfer. Generally speaking, neutral particle beam bombardment of biologic cells was more effective in inducing DNA transfer than charged ionbeam bombardment.

A versatile spectrometer useful for measuring the mass, charge, energy, fluence and angular distribution of primaries and fragments associated with relativistic heavy ionbeams is described. The apparatus is designed to provide accurate physical data for biology experiments and medical therapy planning as a function of depth in tissue. The spectrometer can also be used to measure W, the average energy to produce an ion pair, range-energy, dE/dx, and removal cross section data of interest in nuclear physics. (orig.)

In investigation on ultra-low-energy ion bombardment effect on DNA, an ionbeam deceleration lens was developed for high-quality ultra-low-energy ionbeam. Measurement of the ion energy after deceleration was necessary to confirm the ionbeam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ionbeam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ionbeam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ionbeam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ionbeam line. Moving the measurement rod across the decelerated ionbeam enabled to obtain beam profiles, from which the beam bending distance could be known and the ionbeam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

Electron beamion sources produce very highly charged ions most efficiently in a batch mode as the confinement time can be directly optimized for the production of the desired charge state. If, after confinement, the voltage of the ion-confining downstream dam is lowered rapidly, all ions escape and form an ionbeam pulse with a length of a few tens of μs. Raising the main trap voltage while maintaining a constant dam voltage in a open-quotes spill-over expulsionclose quotes reduces the energy spread of the expelled ions. The longer time periods of open-quotes slow-,close quotes open-quotes leaky batch mode-,close quotes and open-quotes direct current (dc) batch mode-close quotes expulsions allow for increasing the ionbeam duty cycle. Combining the rapid expulsion with one of the latter methods allows for the expulsion of the ions of a single batch in many small microbunches with variable intervals, maintaining the low energy spread and the increased duty cycle of slow expulsions. Combining the open-quotes microbunchingclose quotes with open-quotes dc batch mode productionclose quotes and a multitrap operation will eventually allow for the production of equally intense ion bunches over a wide range of frequencies without any deadtime, and with minimal compromise on the most efficient production parameters. copyright 1998 American Institute of Physics

Ion-acoustic solitons in a collisionless plasma consisting of warm ions, hot isothermal electrons and a electron beam are studied by using the reductive perturbation method. The basic set of fluid equations is reduced to Korteweg-de Vries and modified Korteweg-de Vries temperature and electron beam on ion acoustic equations. The effect of ion solitons are investigated

An overview of the present uses of radioactive ionbeams from ISOLDE for condensed matter research is presented. As simple examples of such work, tracer studies of diffusion processes with radioisotopes and blocking/channeling measurements of emitted particles for lattice location are discussed. Especially the application of nuclear hyperfine interaction techniques such as PAC or Moessbauer spectroscopy has become a powerful tool to study local electronic and structural properties at impurities. Recently, interesting information on impurity properties in semiconductors has been obtained using all these methods. The extreme sensitivity of nuclear techniques makes them also well suited for investigations of surfaces, interfaces, and biomolecules. Some ideas for future uses of high energy radioactive ionbeams beyond the scope of the present projects are outlined: the study of diffusion in highly immiscible systems by deep implantation, nuclear polarization with the tilted-foil technique, and transmutation doping of wide-bandgap semiconductors. (orig.)

Ionbeam diagnostics are routinely used for quantitative analysis of the surface composition of mixture materials up to a depth of a few μm. Unfortunately, advantageous properties of the diagnostics, like high depth resolution in combination with a large penetration depth, no destruction of the surface, high sensitivity for large as well as for small atomic numbers, and high sensitivity are mutually exclusive. Among other things, this is due to the ill-conditioned inverse problem of reconstructing depth distributions of the composition elements. Robust results for depth distributions are obtained with adaptive methods in the framework of Bayesian probability theory. The method of adaptive kernels allows for distributions which contain only the significant information of the data while noise fitting is avoided. This is achieved by adaptively reducing the degrees of freedom supporting the distribution. As applications for ionbeam diagnostics Rutherford backscattering spectroscopy and particle induced X-ray emission are shown

The book provides a detailed, up-to-date account of the basics, the technology, and the clinical use of ionbeams for radiation therapy. Theoretical background, technical components, and patient treatment schemes are delineated by the leading experts that helped to develop this field from a research niche to its current highly sophisticated and powerful clinical treatment level used to the benefit of cancer patients worldwide. Rather than being a side-by-side collection of articles, this book consists of related chapters. It is a common achievement by 76 experts from around the world. Their expertise reflects the diversity of the field with radiation therapy, medical and accelerator physics, radiobiology, computer science, engineering, and health economics. The book addresses a similarly broad audience ranging from professionals that need to know more about this novel treatment modality or consider to enter the field of ionbeam therapy as a researcher. However, it is also written for the interested public an...

The Kolkata Superconducting Cyclotron has already accelerated test beams up to its extraction radius. Efforts are underway to extract the internal beam with the aid of the various extraction elements. A detailed study of the accelerated beams dynamics has been carried out to ensure that before extraction, optimum turn separation is achieved and the beam does not cross the harmful third order coupling resonance, while keeping distortions to a manageable levels. This paper discusses those results and the studies conducted. (author)

The GANIL laboratory has in charge the production of ionbeams for nuclear and non nuclear physics. This article reviews the last developments that are underway in the fields of radioactive ionbeam production, increase of the metallic ion intensities and production of highly charges ionbeams. (authors)

We present characteristics of a 5 MW ion source for SST-1 neutral beam injector. Before the source could be tested for its performance, it was conditioned by 480 arc discharges of 1 s and beamextraction of hydrogen species at various beam voltages ranging between 19 kV and 56 kV. Breakdown free beamextraction could be secured only after about 3000 beam second extraction. The ion source is capable of delivering 1.7 MW of neutral beam power at 55 kV with horizontal and vertical focal length of 5.4 m and 7 m respectively. Beam divergence is {approx}0.97 deg. Steady-state beam energy of 31 MJ at 41 kV was achieved during 14 s long beamextraction. We have not noticed any deterioration of beam parameters, including beam divergence during long pulse operation. These results indicate that 0.5 MW of neutral beam power at 30 kV required for heating of plasma in SST-1 can be delivered.

We present characteristics of a 5 MW ion source for SST-1 neutral beam injector. Before the source could be tested for its performance, it was conditioned by 480 arc discharges of 1 s and beamextraction of hydrogen species at various beam voltages ranging between 19 kV and 56 kV. Breakdown free beamextraction could be secured only after about 3000 beam second extraction. The ion source is capable of delivering 1.7 MW of neutral beam power at 55 kV with horizontal and vertical focal length of 5.4 m and 7 m respectively. Beam divergence is ∼0.97 deg. Steady-state beam energy of 31 MJ at 41 kV was achieved during 14 s long beamextraction. We have not noticed any deterioration of beam parameters, including beam divergence during long pulse operation. These results indicate that 0.5 MW of neutral beam power at 30 kV required for heating of plasma in SST-1 can be delivered.

We have developed an external beam facility for the 1.1-MV tandem Pelletron accelerator in the Union College IonBeam Analysis Laboratory. The beam is extracted from an aluminum pipe through a 1 / 4 ' ' diameter window with a 7.5- μm thick Kapton foil. This external beam facility allows us to perform ionbeam analysis on samples that cannot be put under vacuum, including wet samples and samples too large to fit into the scattering chamber. We have commissioned the new facility by performing proton induced X-ray emission (PIXE) analysis of several samples of environmental interest. These include samples of artificial turf, running tracks, and a human tooth with an amalgam filling. A 1.7-MeV external proton beam was incident on the samples positioned 2 cm from the window. The resulting X-rays were measured using a silicon drift detector and were analyzed using GUPIX software to determine the concentrations of elements in the samples. The results on the human tooth indicate that while significant concentrations of Hg, Ag, and Sn are present in the amalgam filling, only trace amounts of Hg appear to have leached into the tooth. The artificial turf and running tracks show rather large concentrations of a broad range of elements and trace amounts of Pb in the turf infill.

An analytic theory for magnetically insulated, multistage acceleration of high intensity ionbeams, where the diamagnetic effect due to electron flow is important, has been presented by Slutz and Desjarlais. The theory predicts the existence of two limiting voltages called V 1 (W) and V 2 (W), which are both functions of the injection energy qW of ions entering the accelerating gap. As the voltage approaches V 1 (W), unlimited beam-current density can penetrate the gap without the formation of a virtual anode because the dynamic gap goes to zero. Unlimited beam current density can penetrate an accelerating gap above V 2 (W), although a virtual anode is formed. It was found that the behavior of these limiting voltages is strongly dependent on the electron density profile. The authors have investigated the behavior of these limiting voltages numerically using the 2-D particle-in-cell (PIC) code MAGIC. Results of these simulations are consistent with the superinsulated analytic results. This is not surprising, since the ignored coordinate eliminates instabilities known to be important from studies of single stage magnetically insulated ion diodes. To investigate the effect of these instabilities the authors have simulated the problem with the 3-D PIC code QUICKSILVER, which indicates behavior that is consistent with the saturated model

The Electron BeamIon Sources (EBIS), Electron BeamIon Traps (EBIT) and electron beams for electron cooling application have the beam parameters in the same ranges of magnitudes. EBIS and EBIT produce and accumulate ions in the beam due to electron impact ionization. The cooling electron beam accumulates positive ions from the residual gas in the accelerator chamber during the cooling cycle. The space charge neutralization of cooling beam is also used to reduce the electron energy spread and enhance the cooling ability. The advanced results of experimental investigations and theoretical models of the EBIS electron beams are applied to analyze the problem of beam neutralization in the electron cooling techniques. The report presents the analysis of the most important processes connected with ion production, accumulation and losses in the intensive electron beams of ion sources and electron cooling systems for proton and ion colliders. The inelastic and elastic collision processes of charged particles in the electron beams are considered. The inelastic processes such as ionization, charge exchange and recombination change the charge states of ions and neutral atoms in the beam. The elastic Coulomb collisions change the energy of particles and cause the energy redistribution among components in the electron-ionbeams. The characteristic times and specific features of ionization, beam neutralization, ion heating and loss in the ion sources and electron cooling beams are determined. The dependence of negative potential in the beam cross section on neutralization factor is studied. 17 refs., 5 figs., 1 tab

The laser ion source project at the IGISOL facility, Jyvaeskylae, has motivated the development and construction of an rf sextupole ionbeam guide (SPIG) to replace the original skimmer electrode. The SPIG has been tested both off-line and on-line in proton-induced fission, light-ion and heavy-ion induced fusion-evaporation reactions and, in each case, has been directly compared to the skimmer system. For both fission and light-ion induced fusion, the SPIG has improved the mass-separated ion yields by a factor of typically 4-8. Correspondingly, the transmission efficiency of both systems has been studied in simulations with and without space charge effects. The transport capacity of the SPIG has been experimentally determined to be ∼10 12 ions s -1 before space charge effects start to take effect. A direct comparison with the simulation has been made using data obtained via light-ion fusion evaporation. Both experiment and simulation show an encouraging agreement as a function of current extracted from the ion guide.

Modern broad-beam multi-aperture ion sources are widely used in material and surface technology applications. Customizing the generated ionbeam properties (i. e. the ion current density profile) for specific demands of the application is a main challenge in the improvement of the ionbeam technologies. First we introduce ion sources based on different plasma excitation principles shortly. An overview of source plasma and ionbeam measurement methods deliver input data for modelling methods. This beam profile modelling using numerical trajectory codes and the validation of the results by Faraday cup measurements as a basis for ionbeam profile design are described. Furthermore possibilities for ex situ and in situ beam profile control are demonstrated, like a special method for in situ control of a linear ion source beam profile, a grid modification for circular beam profile design and a cluster principle for broad beam sources. By means of these methods, the beam shape may be adapted to specific technological demands. Examples of broad beam source application in ionbeam figuring of optical surfaces, modification of stainless steel, photo voltaic processes and deposition of EUVL-multilayer stacks are finally presented. (Author)

The ionextraction capabilities of accelerator systems with small screen hole diameters (less than 2.0 mm) are investigated at net-accelerating voltages of 100, 300, and 500 V. Results show that the impingement-limited perveance is not dramatically affected by reductions in screen hole diameter to 1.0 mm, but impingement-limited performance was found to be dependent on the grid separation distance, the discharge-to-total accelerating voltage ratio, and the net-to-total accelerating voltage ratio. Results obtained using small hole diameters and closely spaced grids indicate a new mode of grid operation where high current density operation can be achieved with a specified net acceleration voltage by operating the grids at a high rather than low net-to-total acceleration voltage. Beam current densities as high as 25 mA/sq cm were obtained using grids with 1.0 mm diameter holes operating at a net accelerating voltage of 500 V.

The Holifield Radioactive IonBeam Facility (HRIBF) construction project has been completed and the first radioactive ionbeam has been successfully accelerated. The project, which began in 1992, has involved numerous facility modifications. The Oak Ridge Isochronous Cyclotron has been converted from an energy booster for heavy ionbeams to a light ion accelerator with internal ion source. A target-ion source and mass analysis system have been commissioned as key components of the facility's radioactive ionbeam injector to the 25MV tandem electrostatic accelerator. Beam transport lines have been completed, and new diagnostics for very low intensity beams have been developed. Work continues on a unified control system. Development of research quality radioactive beams for the nuclear structure and nuclear astrophysics communities continues. This paper details facility development to date

For the application as a transverse ionbeam diagnostics device, various scintillation screen materials were analysed. The properties of the materials such as light output, image reproduction and radiation stability were investigated with the ionbeamsextracted from heavy ion synchrotron SIS-18. The ion species (C, Ne, Ar, Ta and U) were chosen to cover the large range of elements in the periodic table. The ions were accelerated to the kinetic energies of 200 MeV/u and 300 MeV/u extracted with 300 ms pulse duration and applied to the screens. The particle intensity of the ionbeam was varied from 10{sup 4} to 10{sup 9} particles per pulse. The screens were irradiated with typically 40 beam pulses and the scintillation light was captured using a CCD camera followed by characterization of the beam spot. The radiation hardness of the screens was estimated with high intensity Uranium ion irradiation. In the study, a linear light output for 5 orders of magnitude of particle intensities was observed from sensitive scintillators and ceramic screens such as Al{sub 2}O{sub 3}:Cr and Al{sub 2}O{sub 3}. The highest light output was recorded by CsI:Tl and the lowest one by Herasil. At higher beam intensity saturation of light output was noticed from Y and Mg doped ZrO{sub 2} screens. The light output from the screen depends not only on the particle intensity but also on the ion species used for irradiation. The light yield (i.e. the light intensity normalised to the energy deposition in the material by the ion) is calculated from the experimental data for each ionbeam setting. It is shown that the light yield for light ions is about a factor 2 larger than the one of heavy ions. The image widths recorded exhibit a dependence on the screens material and differences up to 50 % were registered. On radiation stability analysis with high particle intensity of Uranium ions of about 6 x 10{sup 8} ppp, a stable performance in light output and image reproduction was documented from Al

Deposition of thin films using low energy, mass-separated ionbeams is a potentially important low temperature method of producing epitaxial layers. In these experiments silicon films were grown on Si (001) substrates using 10-200 eV 28 Si + and 30 Si + ions at substrate temperatures in the range 273-1073 K, under ultrahigh-vacuum conditions (deposition pressure -7 Pa). The film crystallinity was assessed in situ using medium energy ion scattering (MEIS). Films of crystallinity comparable to bulk samples were grown using 10-40 eV 28 Si + and 30 Si + ions at deposition temperatures in the range 623-823 K. These experiments confirmed the role of key experimental parameters such as ion energy, substrate temperature during deposition, and the surface treatment prior to deposition. It was found that a high temperature in situ anneal (1350-1450 K) gave the best results for epitaxial nucleation, whereas low energy (20-40 eV) Cl + ion bombardment resulted in amorphous film growth. The deposition energy for good epitaxial growth indicates that it is necessary to provide enough energy to induce local mobility but not to cause atomic displacements leading to the buildup of stable defects, e.g. divacancies, below the surface layer of the growing film. (orig.)

Mutation induction using ionizing radiation provides an effective alternative means for improvement of orchids. In this study, ionbeams were used because they have much higher linear energy transfer (LET) than X-rays or gamma rays, and subsequently lead to higher mutation frequency and broad mutation spectrum. The proto corm-like bodies (PLBs) of three orchid species (Dendrobium crumenatum, Dendrobium mirbellianum) were irradiated at various doses with 320 MeV 12 C 6+ ions accelerated by Azimuthally Varying Field (AVF) cyclotron at JAEAs Takasaki Ion Accelerators for Advanced Radiation Application (TIARA). The optimum irradiation condition and the effect of irradiation on each species were studied, particularly on flower colour and morphology, flowering habit and insect resistance. Dose effects on plantlet regeneration for each species were also obtained. Some morphological changes were observed in flowers of Dendrobium crumenatum, whilst one insect resistant mutant was obtained in Dendrobium mirbellianum. (author)

In this topical review, the potential of the focused ionbeam (FIB) technology and ultimate applications are reviewed. After an introduction to the technology and to the operating principles of liquid metal ion sources (LMIS), of ion optics and instrument architectures, several applications are described and discussed. First, the application of FIB for microcircuit inspection, metrology and failure analysis is presented. Then, we introduce and illustrate some advanced patterning schemes we propose as next generation FIB processing examples. These patterning schemes are (i) local defect injection or smoothing in magnetic thin film direct patterning, (ii) functionalization of graphite substrates to guide organization of clusters, (iii) local and selective epitaxy of III–V semiconductor quantum dots and (iv) FIB patterned solid-state nanopores for biological molecules manipulation and analysis. We conclude this work by giving our vision of the future developments for FIB technology. (topical review)

Introduction. The Laboratory of IonBeam Applications of ATOMKI is devoted to applications of atomic and nuclear physics in the fields of environmental research, biomedicine, geology, materials and surface science (including ionbeam induced damage investigations and proton beam lithography) and cultural heritage research. We perform our work in the frame of various projects and collaborations: EU, IAEA, R and D, OTKA, etc. Our laboratory provides service for external (national and international) and internal users and contributes to higher education, as well. The Laboratory is based on the home-made 5 MV Van de Graaff (VdG) electrostatic accelerator of the institute. The accelerator was put into operation in 1971 and in the beginning it supplied ionbeams exclusively for nuclear physics. A few years later with the measurements of K-shell ionization cross sections the door became open also for basic atomic physics. In parallel with this basic study, the application of proton induced X-ray emission (PIXE) for the elemental analysis of biological (hair, erythrocyte and blood plasma) samples and atmospheric aerosols also started. The first paper on PIXE, a methodological one, was published in 1978. The experience gained on these applications and later on archaeology led to the construction of complex PIXE chambers, which were sold, together with the corresponding know-how, to institutions in China, Portugal, Bangladesh, Jordan, North Korea, Singapore, Cuba and Mexico through the International Atomic Energy Agency (IAEA). For the evaluation of PIXE spectra the laboratory has been continuously developing its own computer programme package. The first version of this continuous development was published in 1988. In the meantime a second IBA analysis method, the proton induced gamma ray emission (PIGE), was introduced in the laboratory and was applied simultaneously with PIXE. Application of deuteron induced gamma ray emission (DIGE) started more than a decade later. A

This paper studies the influence of various parameters and conditions on the performance of an ion-beamextraction system, the trajectories of the particles in the beam being simulated by a commercial software (SIMION 3D). Space-charge effects are accounted for and criteria allowing optimization of the system are proposed. Ionbeam trajectories with and without space charge have been determined and, from the results, optimum extraction conditions have been deduced. Simulation of singly charged ion trajectories for a concave meniscus with 3.5 mm curvature radius was studied with and without space charge has been done using a singly charge argon ion trajectories. Firstly, for a concave meniscus with 3.5 mm curvature radius, the influence of the current density on the ionbeam shape was investigated. Furthermore, influence of the extraction voltage applied to the extraction electrode on the ionbeam envelope was studied. Finally, the influence of the extraction gap width on the ionbeam envelope was also studied

The intensity of coherent electromagnetic radiation due to interaction of a modulated electron beam with a modulated ionbeam is calculated. It is shown that the radiation intensity has a sharp maximum at the frequency equal to the difference of the modulation frequency of the electron and ionbeams. The results obtained are compared with those corresponding to the scattering of a modulated electron beam on randomly distributed gas ions.

In the recent years, progress concerning the production of high intensity of metallic ionsbeams ( 58 Ni, 48 Ca, 76 Ge) at Ganil have been performed. The MIV0C method has been successfully used to produce a high intensity nickel beam with the ECR4 ion source: 20 eμA of 58 Ni 11+ at 24 kV extraction voltage. This beam has been maintained for 8 days and accelerated up to 74.5 MeV/u by our cyclotrons with a mean intensity of 0.13 pμA on target. This high intensity, required for experiment, led to the discovery of the doubly magic 48 Ni isotope. The oven method has been first tested with natural metallic calcium on the ECR4 ion source, then used to produce a high power beam (740 W on target i.e. 0.13 pμA accelerated up to 60 MeV/u) of 48 Ca still keeping a low consumption (0.09 mg/h). A germanium beam is now under development, using the oven method with germanium oxide. The ionization efficiencies have been measured and compared. (authors)

The theoretical estimations and numerical simulations of tubular electron beams in both beam and reflex mode of source operation as well as the off-axis ionextraction from a tubular electron beamion source (TEBIS) are presented. Numerical simulations have been done with the use of the IGUN and OPERA-3D codes. Numerical simulations with IGUN code show that the effective electron current can reach more than 100 A with a beam current density of about 300-400 A/cm 2 and the electron energy in the region of several KeV with a corresponding increase of the ion output. Off-axis ionextraction from the TEBIS, being the nonaxially symmetric problem, was simulated with OPERA-3D (SCALA) code. The conceptual design and main parameters of new tubular sources which are under consideration at JINR, MSL, and BNL are based on these simulations

A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beamextraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ionbeam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beamextraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.

The current and charge neutralization of charged particle beams by background plasma enable ballistic beam propagation and have a wide range of applications in inertial fusion and high energy density physics. However, the beam-plasma interaction can result in the development of collective instabilities that may have deleterious effects on ballistic propagation of an ionbeam. In the case of fast, light-ionbeams, non-linear fields created by instabilities can lead to significant defocusing of the beam. We study an ionbeam pulse propagating in a background plasma, which is subjected to two-stream instability between the beamions and plasma electrons, using PIC code LSP. The defocusing effects of the instability on the beam can be much more pronounced in small radius beams. We show through simulations that a beamlet produced from an ionbeam passed through an aperture can be used as a diagnostic tool to identify the presence of the two-stream instability and quantify its defocusing effects. The effect can be observed on the Neutralized Drift Compression Experiment-II facility by measuring the spot size of the extracted beamlet propagating through several meters of plasma.

A cocktail ionbeam, a mixture of ion species of nearly the same mass-to-charge ratio(M/Q), provides a time-saving method for switching one ion species to another using a cyclotron as a mass analyzer. This method is useful for Single Event Effect (SEE) testing to perform irradiations over a wide range of linear energy transfers (LETs) within one experimental time because the beam switching time diminishes from 1 or 2 hours to less than ten minutes, and one cocktail covers a wide LET range. A cocktail of M/Q = 5 covering a range of high LETs (3.3-40 MeV/(mg/cm 2 )) and a cocktail of M/Q=4 covering a range of low LETs (0.2-36 MeV/(mg/cm 2 )) have been developed. Impurities in the extractedbeam caused by insufficient separation, which give ambiguity to the LET data, have been eliminated by specific methods. (author)

Here we examine the potential of serial Broad IonBeam (BIB) Ar{sup +} ion polishing as an advanced serial section tomography (SST) technique for destructive 3D material characterisation for collecting data from volumes with lateral dimensions significantly greater than 100 µm and potentially over millimetre sized areas. Further, the associated low level of damage introduced makes BIB milling very well suited to 3D EBSD acquisition with very high indexing rates. Block face serial sectioning data registration schemes usually assume that the data comprises a series of parallel, planar slices. We quantify the variations in slice thickness and parallelity which can arise when using BIB systems comparing Gatan PECS and Ilion BIB systems for large volume serial sectioning and 3D-EBSD data acquisition. As a test case we obtain 3D morphologies and grain orientations for both phases of a WC-11%wt. Co hardmetal. In our case we have carried out the data acquisition through the manual transfer of the sample between SEM and BIB which is a very slow process (1–2 slice per day), however forthcoming automated procedures will markedly speed up the process. We show that irrespective of the sectioning method raw large area 2D-EBSD maps are affected by distortions and artefacts which affect 3D-EBSD such that quantitative analyses and visualisation can give misleading and erroneous results. Addressing and correcting these issues will offer real benefits when large area (millimetre sized) automated serial section BIBS is developed. - Highlights: • In this work we examine how microstructures can be reconstructed in three-dimensions (3D) by serial argon broad ionbeam (BIB) milling, enabling much larger volumes (>250×250×100µm{sup 3}) to be acquired than by serial section focused ionbeam-scanning electron microscopy (FIB-SEM). • The associated low level of damage introduced makes BIB milling very well suited to 3D-EBSD acquisition with very high indexing rates. • We explore

A focused ionbeam has been used to mill both individual carbon fibres as well as fibres in an epoxy composite, with a view to preparing flat surfaces for nano-indentation. The milled surfaces have been assessed for damage using scanning probe microscopy nano-indentation and Raman micro-probe analysis, revealing that FIB milling damages the carbon fibre surface and covers surrounding areas with debris of disordered carbon. The debris is detected as far as 100 μm from the milling site. The energy of milling as well as the orientation of the beam was varied and shown to have an effect when assessed by Raman spectroscopy. - Highlights: • Focused ionbeam (FIB) milling was used to mill flat surfaces on carbon fibres. • Raman spectroscopy showed amorphous carbon was generated during FIB milling. • The amorphous debris is detected as far as 100 μm from the milling site. • This surface degradation was confirmed by nano-indentation experiments.

High dose ion bombardment of silicon with reactive species, such as oxygen and nitrogen, has attracted considerable interest due to possible applications of beam-induced chemical compounds with silicon. For example, high energy oxygen bombardment of Si is now routinely used to form buried oxide layers for device purposes, the so called SIMOX structures. On the other hand, Si nitrides, formed by low energy ( 100 keV) nitrogen beam bombardment of Si, are attractive as oxidation barriers or gate insulators, primarily due to the low diffusivity of many species in Si nitrides. However, little data exists on silicon nitride formation during bombardment and its angle dependence, in particular for N 2 + bombardment in the 10 keV range, which is of interest for analytical techniques such as SIMS. In SIMS, low energy oxygen ions are more commonly used as bombarding species, as oxygen provides stable ion yields and enhances the positive secondary ion yield. Therefore, a large body of data can be found in the literature on oxide formation during low energy oxygen bombardment. Nitrogen bombardment of Si may cause similar effects to oxygen bombardment, as nitrogen and oxygen have similar masses and ranges in Si, show similar sputtering effects and both have the ability to form chemical compounds with Si. In this work we explore this possibility in some detail. We compare oxide and nitride formation during oxygen and nitrogen ion bombardment of Si under similar conditions. Despite the expected similar behaviour, some large differences in compound formation were found. These differences are explained in terms of different atomic diffusivities in oxides and nitrides, film structural differences and thermodynamic properties. (author)

In directly writing the 30 nm focus of a focussed Ga-ionbeam (FIB) with an energy of 100 keV we define insulating lines in two-dimensional electronic layers in semiconductors. Ga ions act in GaAs and silicon as deep impurities or p-type doping, respectively. In this way the insulation by such written lines is due to lateral depletion within npn-like interfaces. In writing two FIB lines with a close spacing we define conducting channels between them. In applying a voltage of several Volts to the adjacent areas of the channel relative to it we can tune the effective width of the channel in the range of a few 100 nm to zero and obtain thus a one-dimensional field-effect-transistor-type structure. This transistor exhibits a pure lateral field effect and is thus topologically very different to current transistor concepts. Due to its particular geometry it is called in-plane-gate (IPG) transistor, since the gate and the channel are in the same plane. The fabrication of this type of transistor is thus completely maskless and does not require any alignment procedures since gate, source and drain are all written in the same writing process. Due to the computer-control of the beam deflection even more complex structures are just a question of software and do not need a set of specific masks or photoresist like in the classical lithography. The required line ion dose is of the order of 10 6 cm -1 which means that there are about 100 ions per μm implanted. For devices with maximum micron dimensions only a few hundred ions need thus to be implanted. (orig.)

The LHC beam dump system must function safely with 208Pb82+ions. The differences with respect to the LHC proton beams are briefly recalled, and the possible areas for performance concerns discussed, in particular the various beam intercepting devices and the beam instrumentation. Energy deposition simulation results for the most critical elements are presented, and the conclusions drawn for the lead ion operation. The expected performance of the beam instrumentation systems are reviewed in the context of the damage potential of the ionbeam and the required functionality of the various safety and post-operational analysis requirements.

Object of the present thesis was the systematic study of ion-beam induced structure modifications in amorphous germanium (a-Ge) layers due to low- (LEI) and high-energetic (SHI) ion irradiation. The LEI irradiation of crystalline Ge (c-Ge) effects because the dominating nuclear scattering of the ions on the solid-state atoms the formation of a homogeneous a-Ge Layer. Directly on the surface for fluences of two orders of magnitude above the amorphization fluence the formation of stable cavities independently on the irradiation conditions was observed. For the first time for the ion-beam induced cavity formation respectively for the steady expansion of the porous layer forming with growing fluence a linear dependence on the energy ε n deposed in nuclear processes was detected. Furthermore the formation of buried cavities was observed, which shows a dependence on the type of ions. While in the c-Ge samples in the range of the high electronic energy deposition no radiation defects, cavities, or plastic deformations were observed, the high electronic energy transfer in the 3.1 μm thick pre-amorphized a-Ge surface layers leads to the formation of randomly distributed cavities. Basing on the linear connection between cavity-induced vertical volume expansion and the fluence determined for different energy transfers for the first time a material-specific threshold value of ε e HRF =(10.5±1.0) kev nm -1 was determined, above which the ion-beam induced cavity formation in a-Ge sets on. The anisotropic plastic deformation of th a-Ge layer superposed at inclined SHI irradiation on the cavity formation was very well described by an equation derived from the viscoelastic Maxwell model, but modified under regardment of the experimental results. The positive deformation yields determined thereby exhibit above a threshold value for the ion-beam induced plastic deformation ε e S a =(12±2) keV nm -1 for the first time extracted for a Ge the characteristic linear behaviour of the

Use of a high-power electron linac as the driver accelerator for a Radioactive IonBeam (RIB) facility is proposed. An electron beam of 30 MeV and 100 kW can produce nearly 5x10 sup 1 sup 3 fissions/s from an optimized sup 2 sup 3 sup 5 U target and about 60% of this from a natural uranium target. An electron beam can be readily transmitted through a thin window at the exit of the accelerator vacuum system and transported a short distance through air to a water-cooled Bremsstrahlung-production target. The Bremsstrahlung radiation can, in turn, be transported through air to the isotope-production target. This separates the accelerator vacuum system, the Bremsstrahlung target and the isotope-production target, reducing remote handling problems. The electron beam can be scanned over a large target area to reduce the power density on both the Bremsstrahlung and isotope-production targets. These features address one of the most pressing technological challenges of a high-power RIB facility, namely the production o...

A collaboration project between the School of Dentistry and the Institute of Physics of the University of Sao Paulo has been established to measure elemental concentrations in teeth by proton induced X-ray emission (PIXE) and heavy ion elastic recoil detection analysis (HI-ERDA) techniques. Data on trace elements in human, bovine and swine teeth, analyzed by PIXE with a 2.4 MeV proton beam, were compared and concentrations for several elements were obtained with tens of μg/g sensitivity. HI-ERDA measurements employing a 52 MeV Cl beam were done to evaluate changes in elementary concentration in dental enamel after bleaching treatment with different products in 25 bovine incisors teeth. This nondestructive technique allowed the measurements of Ca, P, O and C concentrations above the limit of 100 μg/g. (author)

An analysis is given for the structure of the deflagration wave which is formed in a target bombarded by an ionbeam. Stationary deflagration and/or detonation waves are formed at the surface of the target in a case in which the reaction energy of direct fusion and/or the beam energy deposited in the target are less than a critical value. On the other hand, no solution for stationary wave exists, if the energy deposited in the wave exceeds a critical value. In the latter case, the time-dependent fundamental equations reduce approximately to a self-similar type of equations. Numerical integrations are carried out for this type of differential equations, and an example of self-similar deflagration wave numerically obtained is plotted in the figures. (author)

A Monte Carlo program for the simulation of ionbeam analysis data is presented. It combines mainly four features: (i) ion slowdown is computed separately from the main scattering/recoil event, which is directed towards the detector. (ii) A virtual detector, that is, a detector larger than the actual one can be used, followed by trajectory correction. (iii) For each collision during ion slowdown, scattering angle components are extracted form tables. (iv) Tables of scattering angle components, stopping power and energy straggling are indexed using the binary representation of floating point numbers, which allows logarithmic distribution of these tables without the computation of logarithms to access them. Tables are sufficiently fine-grained that interpolation is not necessary. Ion slowdown computation thus avoids trigonometric, inverse and transcendental function calls and, as much as possible, divisions. All these improvements make possible the computation of 10 7 collisions/s on current PCs. Results for transmitted ions of several masses in various substrates are well comparable to those obtained using SRIM-2006 in terms of both angular and energy distributions, as long as a sufficiently large number of collisions is considered for each ion. Examples of simulated spectrum show good agreement with experimental data, although a large detector rather than the virtual detector has to be used to properly simulate background signals that are due to plural collisions. The program, written in standard C, is open-source and distributed under the terms of the GNU General Public License

Focused ionbeams are currently being investigated for many submicron fabrication and analytical purposes. An FIB micromachining system consisting of a UHV vacuum system, a liquid metal ion gun, and a control and data acquisition computer has been constructed. This system is being used to develop nanofabrication and nanomachining techniques involving focused ionbeams and scanning tunneling microscopes.

Efforts are underway at Los Alamos National Laboratory to utilize plasma and intense ionbeam science and technology of the processing of advanced materials. A major theme involves surface modification of materials, e.g., etching, deposition, alloying, and implantation. In this paper, we concentrate on two programs, plasma source ion implantation and high-intensity pulsed ionbeam deposition

A beam profile monitor for heavy ionbeams has been developed for the use in experiments at the Heavy Ion Synchrotron SIS at Gesellschaft fuer Schwerionenforschung Darmstadt (GSI). Four thin scintillation fibres are mounted on one wheel and scan the ionbeam sequentially in two linearly independent directions. They are read out via one single photomultiplier common to all four fibres into one time spectrum, which provides all information about beam position, beam extension, time structure and lateral homogeneity of the beam. The system operates in a wide dynamic range of beam intensities. ((orig.))

The planned Facility for Antiproton and Ion Research (FAIR) at GSI has to cope with a wide range of beam intensities in its high-energy beam transport systems and in the storage rings. To meet the requirements of a non-intercepting intensity measurement down to nA range, it is planned to install a number of Cryogenic Current Comparator (CCC) units at different locations in the FAIR beamlines. In this work, the first CCC system for intensity measurement of heavy ionbeams, which was developed at GSI, was re-commissioned and upgraded to be used as a 'GSI - CCC prototype' for extensive optimization and development of an improved CCC for FAIR. After installation of a new SQUID sensor and related electronics, as well as implementation of improved data acquisition components, successful beam current measurements were performed at a SIS18 extraction line. The measured intensity values were compared with those of a Secondary Electron Monitor (SEM). Furthermore, the spill-structure of a slowly extractedbeam was measured and analyzed, investigating its improvement due to bunching during the slow-extraction process. Due to the extreme sensitivity of the superconducting sensor, the determined intensity values as well as the adjustment of the system for optimal performance are strongly influenced by the numerous noise sources of the accelerators environment. For this reason, detailed studies of different effects caused by noise have been carried out, which are presented together with proposals to reduce them. Similarly, studies were performed to increase the dynamic range and overcome slew rate limitations, the results of which are illustrated and discussed as well. By combining the various optimizations and characterizations of the GSI CCC prototype with the experiences made during beam operation, criteria for a more efficient CCC System could be worked out, which are presented in this work. The details of this new design are worked out with respect to the

The variety of new research possibilities afforded by the culmination of the two frontier areas of nuclear structure: high spin and studies far from nuclear stability (utilizing intense radioactive ionbeams) are discussed. Topics presented include: new regions of exotic nuclear shape (e.g. superdeformation, hyperdeformation, and reflection-asymmetric shapes); the population of and consequences of populating exotic nuclear configurations; and complete spectroscopy (i.e. the overlap of state of the art low-and high-spin studies in the same nucleus)

The variety of new research possibilities afforded by the culmination of the two frontier areas of nuclear structure: high spin and studies far from nuclear stability (utilizing intense radioactive ionbeams) are discussed. Topics presented include: new regions of exotic nuclear shape (e.g. superdeformation, hyperdeformation, and reflection-asymmetric shapes); the population of and consequences of populating exotic nuclear configurations; and, complete spectroscopy (i.e. the overlap of state of the art low- and high-spin studies in the same nucleus). (author). 47 refs., 8 figs.

Ionbeams can be used to probe magnetic properties of surfaces by a variety of different methods. Important features of these methods are related to trajectories of atomic projectiles scattered from the surface of a solid target and to the electronic interaction mechanisms in the surface region. Both items provide under specific conditions a high sensitivity for the detection of magnetic properties in the region at the topmost layer of surface atoms. This holds in particular for scattering under planar surface channeling conditions, where under grazing impact atoms or ions are reflected specularly from the surface without penetration into the subsurface region. Two different types of methods are employed based on the detection of the spin polarization of emitted or captured electrons and on spin blocking effects for capture into atomic terms. These techniques allow one to probe the long range and short range magnetic order in the surface region

A hydrogen high temperature plasma up to 200 eV is produced by acceleration of electrons in a hot hollow cathode discharge and is used as an ionbeam source. Then, two characteristics are observed: A rate of the atomic ion (H + ) number increases above 70%. A perveance of the ionbeam increases above 30 times compared with that of a cold plasma, while a floating potential of an ion acceleration electrode approaches an ion acceleration potential (- 500 V) according as an increment of the electron temperature. Moreover, a neutralized ionbeam can be produced by only the negative floating electrode without an external power supply. (author)

The LHC beam dumping system must safely abort the LHC beams under all conditions, including those resulting from abnormal behaviour of machine elements or subsystems of the beam dumping system itself. The extraction channels must provide sufficient aperture both for the circulating and extractedbeams, over the whole energy range and under various beam parameters. These requirements impose tight constraints on the tolerances of various extraction channel components, and also on the allowed range of beam positions in the region of these components. Operation of the beam dumping system under various fault states has been considered, and the resulting apertures calculated. After describing briefly the beam dumping system and the extraction channel geometry, the various assumptions made in the analysis are presented, before deriving tolerance limits for the relevant equipment and beam parameters.

The present work investigates the plasma characteristics in a constricted R. F. ion source. The extraction of ions from the plasma boundary and sheath formation were studied. The ion source physical parameters are discussed in order to understand the physical processes occurring within the discharge region up to the extraction system. Electron temperature and density were determined using Langmuir probe. The probe current-voltage characteristics were measured for different extraction voltages (ext.) = 0,500,1000, and 1250 volt at various constant R.F. powers. The effect of R.F. power on electron temperature was deduced for a beam = plasma discharge. This revealed that for a quasi-neutral (plasma) region the electron temperature increased linearly with the R.F. Power which leads to substantial electron heating and efficient electron energy transport in this region. Applying extraction voltage, the electron temperature drops as the ionization rate increases. The sheath thickness was obtained at constant extraction voltages. The curves show that if the ion current density increased, the sheath thickness decreased while it increases by increasing extraction voltage, and it is negligible in the plasma region. 13 figs.

The MIVOC method has been successfully used at GANIL to produce a high intensity nickel beam with the ECR4 ion source: 20 μA 58 Ni 11+ at 24 kV extraction voltage. This beam has been maintained for 8 days and accelerated up to 74.5 MeV/u by our cyclotrons with a mean intensity of 0.13 pμA on target. This high intensity, required for experiment, led to the discovery of the doubly magic 48 Ni isotope. Experimental setup, handling and off-line preparation using a residual gas analyzer are described in this report. The ion source behavior, performances and limitations are presented in the case of nickel and iron. The ionization efficiencies have been measured and compared to the oven method usually used at GANIL. (author)

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ionbeam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ionbeams for HIRFL facility since May 2007.

Recent experimental programs at RIKEN concerning RI beams are reviewed. RIKEN has the ring cyclotron (RRC) with high intense heavy-ionbeams and large acceptance fragment separator, RIPS. The complex can provide high intense RI-beams. By using the high intense RI-beams, a variety of experiments have been ...

This paper suggests several current atomic physics questions important to ionbeam fusion. Among the topics discussed are beam transport, beam-target interaction, and reactor design. The major part of the report is discussion concerning areas of research necessary to better understand beam-target interactions

A source of negative deuterium ions in the multi-ampere range is described that is readily extrapolated to reactor size, 10 amp or more of neutral beam, that is of interest in future experiments and reactors. The negative ion source is based upon the double charge exchange process. A beam of positive ions is created and accelerated to an energy at which the attachment process D + M → D - + M + proceeds efficiently. The positive ions are atomically neutralized either in D 2 or in the charge exchange medium M. Atomic species make a second charge exchange collision in the charge target to form D - . For a sufficiently thick target, the beam reaches an equilibrium fraction of negative ions. For reasons of efficiency, the target is typically alkali metal vapor; this experiment uses sodium. The beam of negative ions can be accelerated to high (>200 keV) energy, the electrons stripped from the ions, and a high energy neutral beam formed

This volume containing the proceedings of the national seminar on physics with radioactive ionbeams gives a broad overview of the developments taking place in the area of nuclear physics and accelerator physics with special emphasis on the utilization of radioactive ionbeams for various studies. Topics covered include studies on nuclear structure and nuclear astrophysics and the wide ranging applications of radioactive ionbeams in these and other areas of nuclear sciences. Papers relevant to INIS are indexed separately

A radiofrequency-quadrupole ion accumulator and buncher has been set-up for the low-energy-beam and ion-trap (LEBIT) facility, which is in its final commissioning phase at the NSCL/MSU. The buncher is a cryogenic system with separated cooling and accumulation stages, optimized for excellent beam quality and high performance. The completed set-up of the LEBIT ion buncher is presented as well as first experimental results on pulse forming and beam properties. (orig.)

A radiofrequency-quadrupole ion accumulator and buncher has been set-up for the low-energy-beam and ion-trap (LEBIT) facility, which is in its final commissioning phase at the NSCL/MSU. The buncher is a cryogenic system with separated cooling and accumulation stages, optimized for excellent beam quality and high performance. The completed set-up of the LEBIT ion buncher is presented as well as first experimental results on pulse forming and beam properties. (orig.)

Highlights: ► An ionbeam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ionbeam energy was measured using an electrical field. ► Decelerated ultra-low-energy ionbeam bombarded naked DNA. ► Ionbeam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ionbeam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ionbeam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ionbeam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ionbeam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ionbeam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

Highlights: ► An ionbeam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ionbeam energy was measured using an electrical field. ► Decelerated ultra-low-energy ionbeam bombarded naked DNA. ► Ionbeam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ionbeam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ionbeam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ionbeam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ionbeam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ionbeam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells

Helium and carbon ions enable a more conformal dose distribution, narrower penumbra and higher relative biological effectiveness than photon and proton radiotherapy. However, they may undergo nuclear fragmentation in the patient tissues and the arising secondary fragments affect the delivered biological dose distributions. Currently there is a lack of data regarding ion nuclear fragmentation. One reason is the large size (up to some meters) of the experimental setups required for the investigations. In this thesis a new method is presented, which makes use of versatile pixelated semiconductor detectors (Timepix). This method is based on tracking of single particles and pattern recognition of their signals in the detectors. Measurements were performed at the HIT facility. The mixed radiation field arising from 430 MeV/u carbon ionbeams and 221 MeV/u helium ionbeams in water and in PMMA targets was investigated. The amounts of primary (carbon or helium) ions detected behind targets with the same water equivalent thickness (WET) were found to be in agreement within the statistical uncertainties. However, more fragments (differences up to 20% in case of H) and narrower lateral particle distributions were measured behind the PMMA than the water targets. The spectra of ions behind tissue surrogates and corresponding water targets with the same WET were analysed. The results obtained with adipose and inner bone surrogates and with the equivalent water phantoms were found to be consistent within the uncertainties. Significant differences in the results were observed in the case of lung and cortical bone surrogates when compared to the water phantoms. The experimental results were compared to FLUKA Monte Carlo simulations. This comparison could contribute to enhance the ion interaction models currently implemented for {sup 12}C and {sup 4}He ionbeams.

We review research investigating the application of intense pulsed ionbeams (IPIBs) for the surface treatment and coating of materials. The short range (0.1-10 μm) and high-energy density (1-50 J/cm 2 ) of these short-pulsed (≤ 1 μs) beams (with ion currents I = 5 - 50 kA, and energies E = 100 - 1000 keV) make them ideal to flash-heat a target surface, similar to the more familiar pulsed laser processes. IPIB surface treatment induces rapid melt and solidification at up to 10 10 K/s to cause amorphous layer formation and the production of non-equilibrium microstructures. At higher energy density the target surface is vaporized, and the ablated vapor is condensed as coatings onto adjacent substrates or as nanophase powders. Progress towards the development of robust, high-repetition rate IPIB accelerators is presented along with economic estimates for the cost of ownership of this technology

Ionbeam sputtering (IBS) offers, in contrast to other physical vapour deposition techniques, such as magnetron sputtering or electron beam evaporation, the opportunity to change the properties of the layer forming particles (sputtered and scattered particles) by varying ionbeam parameters (ion species, ion energy) and geometrical parameters (ion incidence angle, emission angle). Consequently, these effects can be utilized to tailor thin film properties [1]. The goal is to study systematically the correlations between the primary and secondary parameters and, at last, the effects on the properties of Si thin films, such as optical properties, stress, surface topography and composition. First experimental results are presented for Ar-ion sputtering of Si.

This document summarises the key feasibility issues associated with the SPS extraction and beam transfer systems required for the SHiP facility. It describes the expected performance limits of the electrostatic septa, the expected beam losses during extraction and consequences, the design of the new beamline geometry and equipment systems and the expected extracted spill structure.

Technology of cyclotron has been actively developed to meet the increasing requirement output of medical radioactive isotopes for PET. KOTRON-13 is produced with low negative hydrogen ionbeam current owing to the low efficiency of proton beam current compared with foreign cyclotron. In the defect there from, the lifetime of cathode is around 5,000min, which requires frequent maintenance period, and the target beam current is maximum 50uA at a poor efficiency compared with the inflow quantity of hydrogen gas and that of inflicting arc current. Considering above affairs, we have to improve the PIG ion source extraction efficiency of KOTRON-13 in order to lift beam current. Mostly the ion source of cyclotron less than 30Mev comes from the use of PIG ion source mainly with the method of cold cathode or hot cathode. However, the cyclotron of 30Mev grade of EBCO or IBA uses the external ion source and uses ion source with cusp type of good withdrawal efficiency. This type requires high voltage, and transports ion from ion source to cyclotron, which requires precise transportation equipment. And entering cyclotron requires a high quality of inflictor with a high defect rate, but high current cyclotron has no choice but to use ion source of such a method. But the cyclotron using PET with the beam current less than 100uA uses PIG ion source of KOTRON-13 with a reasonable maintenance cost

Full text: This paper report various items of recent progress in the theory of field evaporation and the theory of the liquid-metal ion source. The research has, in part, been driven by a desire to find out how to reduce the beam-spot size in a focused ionbeam machine, which is developing as a significant tool of nanotechnology. A major factor in determining beam spot size seems to be the behavior of the liquid-metal ion source (LMIS), and one route might be to reduce the minimum emission current of a LMIS, if this is possible. Theories of LMIS minimum emission current have been re-examined. Some progress has been made, but development of more accurate theory has been constrained by several factors, include the long-known limitations of the present theory of field evaporation (FEV). This, in turn, has stimulated a wider re-examination of FEV theory. As part of some general theoretical remarks, the following items of recent progress will be covered. Various results concerning the prediction of the field F e at which the activation energy Q for field evaporation is zero, including calculations in which vacuum electrostatic energy changes are taken into account, and another look at the views of Kingham and Tsong concerning escape charge-state. Some years ago, the following approximate formula was derived for the dependence of FEV activation energy on field F: Q=B(F e /F - 1) 2 . It has recently been possible to show that the parameter B can be estimated as B= βYΩ/8, where Y is Young's modulus, Ω is the atomic volume, and β is a correction factor of order. In the framework of the charge-draining mechanism, another look at how the activation-energy hump can be modelled, in order to predict/explain the conditions under which FEV becomes dominated by ion tunnelling rather than field evaporation. A review of the changes in LMIS theory that result from applying the equation of continuity to the metal/vacuum interface, including modifications to the theory of minimum

During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport, and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ionbeams by >50X propagating through background plasma enable initial beam target experiments in warm dense matter to begin within the next two years. We are assessing how these new techniques might apply to heavy ion fusion drivers for inertial fusion energy

The positive ion based source with a hot cathode based arc chamber and a tetrode accelerator was employed for a neutral beam injector on the experimental advanced superconducting tokamak (EAST). Four ion sources were developed and each ion source has produced 4 MW @ 80 keV hydrogen beam on the test bed. 100 s long pulse operation with modulated beam has also been tested on the test bed. The accelerator was upgraded from circular shaped to diamond shaped in the latest two ion sources. In the latest campaign of EAST experiment, four ion sources injected more than 4 MW deuterium beam with beam energy of 60 keV into EAST

A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ionbeams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 10(13) W cm(-2) in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ionbeam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ionbeams, modification of the ionbeam pulse duration, and reliability of the ion source still need to be made for practical applications.

To investigate the effect of local irradiation with ionbeams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ionbeams suggests that the efficient pollen envelope damages would be induced at the range-end of ionbeams. (author)

Production of highly intense ionbeams of 48 Ca is one of the main tasks in experiments carried out within the framework of the synthesis of new superheavy elements. 48 Ca is very rare and expensive isotope, therefore there is necessity to reach the high intensity of ionbeams of the isotope at a low consumption rate. Analysis and our preliminary experiments have showed that the best way of producing highly intense calcium ionbeams is evaporation of metallic calcium in an ECR ion source. So we have developed a technique of metallic 48 Ca production by reducing CaO (this chemical form is available at the market with 40-80% of 48 Ca ) with aluminium powder. We used two tantalum crucibles: a larger, with a mixture of CaO + Al heated up to 1250 deg C, which was connected to the smaller (2 mm I.D. and 30 mm long) in which calcium vapour condensed. The temperature distribution in the small crucible was about 50 deg C at the bottom and about 500 deg C in the middle of the crucible. The pressure inside of the set-up was between 0.1 and 1 Pa. The production rate of metallic 48 Ca was 10-20 mg/h. The crucible with the condensed metallic Ca in argon atmosphere was transferred to the ECR-4M ion source, where it was inserted in a wired tubular oven and the calcium evaporation was controlled through the oven power supply. The application of metallic 48 Ca as the working substance for the ECR-4M ion source of the U-400 cyclotron of allowed us to approach a stable high intensity of 48 Ca ionbeams: the intensities for the internal and external beams were 10 13 c -1 and 3.10 12 c -1 , respectively, at a consumption rate about 0.4 mg/h. A technique was developed for the reclamation of 48 Ca from the residue inside of the large crucible and from the inner parts of the ECR ion source. Extracting Ca from the inner parts of the ion source enabled us to save up to some 25% of the calcium used in the ECR ion source, so that the actual consumption rate was about 0.3 mg/h at the highest 48

Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a figure of merit frequently used to determine the quality of ionbeams, the compatibility of an ionbeam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally, a high-quality beam is characterized by a small emittance. In order to determine and improve the quality of ionbeams used at the Holifield Radioactive IonBeam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ionbeams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profiles, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fitting are also incorporated into the software. The software will provide a simplified, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate

Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a fi gure of merit frequently used to determine the quality of ionbeams, the compatibility of an ionbeam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally a high quality beam is characterized by a small emittance. In order to determine and improve the quality of ionbeams used at the Holifi eld Radioactive Ionbeam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ionbeams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profi les, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fi tting are also incorporated into the software. The software will provide a simplifi ed, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate.

Highlights: ► We present an overview of beam diagnostic tools foreseen for the new testbed ELISE. ► A sophisticated diagnostic calorimeter allows beam profile measurement. ► A tungsten wire mesh in the beam path provides a qualitative picture of the beam. ► Stripping losses and beam divergence are measured by H α Doppler shift spectroscopy. -- Abstract: The test facility ELISE, presently being commissioned at IPP, is a first step in the R and D roadmap for the RF driven ion source and extraction system of the ITER NBI system. The “half-size” ITER-like test facility includes a negative hydrogen ion source that can be operated for 1 h. ELISE is expected to extract an ionbeam of 20 A at 60 kV for 10 s every 3 min, therefore delivering a total power of 1.2 MW. The extraction area has a geometry that closely reproduces the ITER design, with the same width and half the height, i.e. 1 m × 1 m. This paper presents an overview of beam diagnostic tools foreseen for ELISE. For the commissioning phase, a simple beam dump with basic diagnostic capabilities has been installed. In the second phase, the beam dump will be substituted by a more sophisticated diagnostic calorimeter to allow beam profile measurement. Additionally, a tungsten wire mesh will be introduced in the beam path to provide a qualitative picture of beam size and position. Stripping losses and beam divergence will be measured by means of H α Doppler shift spectroscopy. An absolute calibration is foreseen in order to measure beam intensity

A negative-ion-based neutral beam injector (N-NBI) has been constructed for JT-60U. The N-NBI is designed to inject 500 keV, 10 MW neutral beams using two ion sources, each producing a 500 keV, 22 A D{sup -} ionbeam. Beam acceleration test started in July, 1995 using one ion source. In the preliminary experiment, D{sup -} ionbeam of 13.5 A has been successfully accelerated with an energy of 400 keV (5.4 MW) for 0.12 s at an operating pressure of 0.22 Pa. This is the highest D{sup -} beam current and power in the world. Co-extracted electron current was effectively suppressed to the ratio of Ie/I{sub D}- <1. The highest energy beam of 460 keV, 2.4 A, 0.44 s has also been obtained. Neutral beam injection starts in March, 1996 using two ion sources. To realize 1 MeV class NBI system for ITER (International Thermonuclear Experimental Reactor), demonstration of ampere class negative ionbeam acceleration up to 1 MeV is an important mile stone. To achieve the mile stone, a high energy test facility called MeV Test Facility (MTF) was constructed. The system consists of a 1 MV, 1 A acceleration power supply and a 100 kW power supply system for negative ion production. Up to now, an H{sup -} ionbeam was accelerated up to the energy of 805 keV with an acceleration drain current of 150 mA for 1 s in a five stage electrostatic multi-aperture accelerator. (author)

The longitudinal Schottky spectra of a radio-frequency (RF) bunched and electron cooled 22Ne 10+ ionbeam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring (CSRe), at IMP. For an RF-bunched ionbeam, a longitudinal momentum spread of Δp/p=1.6 × 10 -5 has been reached with less than 107 stored ions. The reduction of momentum spread compared with a coasting ionbeam was observed from Schottky noise signal of the bunched ionbeam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25 th , 50 th and 75 th harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ionbeams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ionbeams and nuclear physics at the CSRe. (authors)

A prototype ion source for JT-60 neutral beam injectors has been fabricated and tested. Here, we review the construction of the prototype ion source and report the experimental results about the source characteristics that has been obtained at this time. The prototype ion source is now installed at the prototype unit of JT-60 neutral beam injection units and the demonstration of the performances of the ion source and the prototype unit has just started

Magnetic multipole plasma confinement geometries employing permanent magnet ''buckets'' are used extensively for a range of laboratory plasma applications. Among the several consequences for plasma confinement is the important result that the plasma can acquire a more-or-less flat density profile, which when embodied in an ion source, can also lead to a flat profile for the extractedionbeam. For many applications a uniform ionbeam current density profile is quite advantageous, for example, for carrying out large-area ion implantation. There are, however, inherent limitations on the extent to which this approach to beam ''homogenization'' can be utilized, and even for a perfectly flat profile in the immediate postextraction region, the beam will evolve toward Gaussian as it propagates downstream. Here we describe the rare-earth permanent magnet bucket that we have incorporated into our broad-beam vacuum arc ion source, and its effect on the beam profile at the extractor and downstream. The experimental results are compared with a simple model for the beam profile evolution with axial distance. We find that the beam loses memory of its initially flat profile and relaxes to a more-or-less Gaussian shape in a relatively short axial distance ∼w/4θ, where w is the initial width of the flat beam profile and θ is the beamlet divergence half angle. (c) 2000 American Institute of Physics

A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ionbeams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface

The mechanism of negative ionextraction under real conditions with the complex magnetic field is studied by using the 3D PIC simulation code. The extraction region of the negative ion source for the negative ion based neutral beam injection system in fusion reactors is modelled. It is shown that the E x B drift of electrons is caused by the magnetic filter and the electron suppression magnetic field, and the resultant asymmetry of the plasma meniscus. Furthermore, it is indicated that that the asymmetry of the plasma meniscus results in the asymmetry of negative ionbeam profile including the beam halo. It could be demonstrated theoretically that the E x B drift is not significantly weakened by the elastic collisions of the electrons with neutral particles

The mechanism of negative ionextraction under real conditions with the complex magnetic field is studied by using the 3D PIC simulation code. The extraction region of the negative ion source for the negative ion based neutral beam injection system in fusion reactors is modelled. It is shown that the E x B drift of electrons is caused by the magnetic filter and the electron suppression magnetic field, and the resultant asymmetry of the plasma meniscus. Furthermore, it is indicated that that the asymmetry of the plasma meniscus results in the asymmetry of negative ionbeam profile including the beam halo. It could be demonstrated theoretically that the E x B drift is not significantly weakened by the elastic collisions of the electrons with neutral particles.

A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ionbeams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ionbeams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

Two-dimensional particle-in-cell simulations of intense heavy ionbeams propagating in an inertial confinement fusion (ICF) reactor chamber are presented. The ballistic-neutralized transport scheme studied uses 4 GeV Pb +1 ionbeams injected into a low-density, gas-filled reactor chamber and the beam is ballistically focused onto an ICF target before entering the chamber. Charge and current neutralization of the beam is provided by the low-density background gas. The ballistic-neutralized simulations include stripping of the beamions as the beam traverses the chamber as well as ionization of the background plasma. In addition, a series of simulations are presented that explore the charge and current neutralization of the ionbeam in an evacuated chamber. For this vacuum transport mode, neutralizing electrons are only drawn from sources near the chamber entrance

A two-dimensional fully electromagnetic particle-in-cell code is used to simulate the interaction of a relativistic electron beam injected into a finite-size background neutral plasma. The simulations show that the background electrons are pushed away from the beam path, forming a neutralizing ion channel. Soon after the beam head leaves the plasma, a virtual cathode forms which travels away with the beam. However, at later times a second, quasi-stationary, virtual cathode forms. Its position and strength depends critically on the parameters of the system which critically determines the efficiency of the ion acceleration process. The background ions trapped in the electrostatic well of the virtual cathode are accelerated and at later times, the ions as well as the virtual cathode drift away from the plasma region. The surfing of the ions in the electrostatic well produces an ion population with energies several times the initial electron beam energy. It is found that optimum ion acceleration occurs when the beam-to-plasma density ratio is near unity. When the plasma is dense, the beam is a weak perturbation and accelerates few ions, while when the plasma is tenuous, the beam is not effectively neutralized, and a virtual cathode occurs right at the injection plane. The simulations also show that, at the virtual cathode position, the electron beam is pinched producing a self-focusing phenomena

High-brightness proton beams (.4 MA, 1 MV) have recently been extracted from 20 cm 2 axial pinch-reflex diodes (PRDs) mounted on the NRL Gamble II generator. A source power brightness of GT 10 TW/cm 2 rad 2 was achieved in these experiments. A new barrel-shaped equitorial PRD that can be coupled to PBFA-II has also been operated on Gamble II and has demonstrated 50% proton efficiency with predominately azimuthally-symmetric charged-particle flow. In other experiments the stopping power of deuterons in hot plasmas was measured using a PRD on Gamble II. Results show about 40% enhancement in stopping power over that in cold targets when the beam was focused to about .25 MA/cm 2 . Research is also being performed on transporting ionbeams in large-diameter channels (>= 2.5 cm) and on a post-transport, plasma-filled, magnetic-focusing section to bring the beam to pellet dimensions. (author)

The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

The extracted-beam-detection system working around the synchrotron Saturne is presented. The whole system is composed of about forty multiwire chambers used for beam tuning and providing beams profiles. Optic beam parameters such as position, divergence, dimension, emittance can be easily measured, or calculated with a program running on a computer. They are working in large range intensity beams (10 2 to 5.10 11 p/cm 2 /s of protons, alpha particles, deutons, pions, tritons and electrons [fr

To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ionbeam platform is under design at IMP. A simple test bench has been set up to test the ionbeam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ionbeams. LAPECR1 source has already been ignited. Some intense low charge state ionbeams have been produced on it, but the first test also reveals that many problems are existing on the ionbeam transmission line. The ionbeam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ionbeam, after being analyzed by a double-focusing analyzer magnet, the selected ionbeam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ionbeam focusing. In this paper, the conceptual design of deceleration system will be discussed

To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ionbeam platform is under design at IMP. A simple test bench has been set up to test the ionbeam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ionbeams. LAPECR1 source has already been ignited. Some intense low charge state ionbeams have been produced on it, but the first test also reveals that many problems are existing on the ionbeam transmission line. The ionbeam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ionbeam, after being analyzed by a double-focusing analyzer magnet, the selected ionbeam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ionbeam focusing. In this paper, the conceptual design of deceleration system will be discussed.

The ionbeam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ionbeam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ionbeam optics, the application of a small pre-acceleration voltage ({approx}100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ionbeam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.

The ionbeam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ionbeam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ionbeam optics, the application of a small pre-acceleration voltage (∼100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ionbeam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.

Full text: University of Surrey has, for the past four years, collaborated with police institutions from across Europe and the rest of the world lo scope potential applications of ionbeam analysis (IBA) in forensic science. In doing this we have consulted practitioners across a range of forensic disciplines, and critically compared IBA with conventional characterisation techniques to investigate the areas in which IBA can add evidential value. In this talk, the results of this feasibility study will be presented, showing the types of sample for which IBA shows considerable promise. We will show how a combination of PIXE with other IBA techniques (EBS, PIGE, MeV-SIMS) can be used to give unprecedented characterisation of forensic samples and comment on the significance of these results for forensic casework. We will also show cases where IBA not appear to add any significant improvement over conventional techniques. (author)

A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ionbeams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

There is currently great interest in combining focused ionbeam (FIB) and scanning electron microscopy technologies for advanced studies of polymeric materials and biological microstructures, as well as for sophisticated nanoscale fabrication and prototyping. Irradiation of electrically insulating materials with a positive ionbeam in high vacuum can lead to the accumulation of charge, causing deflection of the ionbeam. The resultant image drift has significant consequences upon the accuracy and quality of FIB milling, imaging and chemical vapour deposition. A method is described for suppressing ionbeam drift using a defocused, low-energy primary electron beam, leading to the derivation of a mathematical expression to correlate the ion and electron beam energies and currents with other parameters required for electrically stabilizing these challenging materials

The availability of intense, high charge state ionbeams from ECR ion sources has had significant impact not only on the upgrading of cyclotron and synchrotron facilities, but also on multicharged ion collision research, as evidenced by the increasing number of ECR source facilities used at least on a part time basis for atomic physics research. In this paper one such facility, located at the ORNL ECR source, and dedicated full time to the study of multicharged ion collisions, is described. Examples of applications of ECR ion source beams are given, based on multicharged ion collision physics studies performed at Oak Ridge over the last few years. 21 refs., 18 figs., 2 tabs.

This work reports Ga + focused ionbeam nanopatterning to create amorphous defects with periodic square arrays in highly oriented pyrolytic graphite and the use of Raman spectroscopy as a new protocol to test and compare progresses in ionbeam optics, for low fluence bombardment or fast writing speed. This can be ultimately used as a metrological tool for comparing different FIB machines and can contribute to Focused IonBeam (FIB) development in general for tailoring nanostructures with higher precision. In order to do that, the amount of ion at each spot was varied from about 10 6 down to roughly 1 ion per dot. These defects were also analyzed by using high resolution scanning electron microscopy and atomic force microscopy. The sensitivities of these techniques were compared and a geometrical model is proposed for micro-Raman spectroscopy in which the intensity of the defect induced D band, for a fixed ion dose, is associated with the diameter of the ionbeam. In addition, the lateral increase in the bombarded spot due to the cascade effect of the ions on graphite surface was extracted from this model. A semi-quantitative analysis of the distribution of ions at low doses per dot or high writing speed for soft modification of materials is discussed. -- Highlights: → Highly oriented pyrolytic graphite surface is bombarded using a focused ionbeam. → Raman spectroscopy is used to propose a new protocol to test focused ionbeam optics. → Scattering diameter of the ions on HOPG surface is experimentally obtained. → Optical limitations of the ion column in fast writing speed are discussed. → Small level of modifications is considered for changing graphene conductive properties.

Full text: Modern research has provided the means of creating materials structures controlled at the atomic scale. Familiar examples include the formation of hetero-structures grown with atomic precision, nanostructures with designed electronic properties and new organic structures employing the richness of organic chemistry. The current forefront of such materials research includes the creation of new materials for energy and electronics applications. The electron transport properties of these diverse materials, and hence their performance, is invariably linked by the basic interactions at the interface. Interfaces are the critical component, and least understood aspect, of almost all such materials-based structures. Ionbeam analysis, and its role in interfacial definition, will be described in the context of a number of such forefront projects underway at the Rutgers Institute for Advanced Materials, Devices and Nanotechnology (IAMDN). These include: 1) quantitative analysis of self-assembled monolayers on organic single crystals resulting in enhanced surface mobility and more effective organic field effect transistors, 2) monolayer scale interfacial analysis of complex oxide hetero-structures to elucidate the properties of the enhanced two-dimensional electron mobility and 3) characterization of the semiconductor- dielectric interface in the SiC/SiO2 system, with application for energy efficient power transmission. Despite extraordinary advances in synthesis, interface properties continue as an uncontrolled region of hetero-materials formation. Their understanding requires the detailed analysis of a complement of tools including ionbeam analysis. Fellow Researchers: R. A. Bartynski, L.C.Feldman, E. Garfunkel, T. Gustafsson, H.D. Lee, D. Mastrogiovanni, V. Podzorov, L. S. Wielunski, J. R. Williams(Auburn), G. Liu, J. Williams, S. Dhar. (author)

Experimental systems for molecular beam epitaxial growth and ionbeam analysis have been designed and constructed for the research of inorganic functional materials such as thin films and superlattices. (author)

Ionbeam transport line for applied research on U-400 cyclotron, beam diagnostics and data acquisition system for condensed matter studies are described. The main features of Windows-based real time program are considered

The pinched electron beam of a pulsed electron accelerator is used to generate an intense beam of ions. A foil anode and vacuum drift tube are used. The space charge field of the pinched beam in the tube accelerates ions from the foil anode. Ion currents of 10 kA at a density of 5kA/cm 2 with pulse length of 50 ns are obtained using a 5 kJ, 450 kV, 3 Ω diode. (author)

The spatial evolution of a velocity- or density-modulated ionbeam is calculated for stable and unstable ionbeam plasma systems, using the linearized Vlasov-Poisson equations. The propagation properties are found to be strongly dependent on the form of modulation. In the case of velocity...

This annual report summarizes the results of research carried out in 1986 within the framework of the program 'High Energy Density in Matter Produced by Heavy IonBeams' which is funded by the Federal Ministry for Research and Technology. Its initial motivation and its ultimate goal is the question whether inertial confinement can be achieved by intense beams of heavy ions. (orig./HSI)

Generation and focusing of ionbeams using an inverse pinch ion diode with a flat anode has been studied. The ionbeams generated with the inverse pinch ion diode were found to be focused at 120 mm from the anode by the electrostatic field in the diode. The energy and maximum current density of the ionbeams were 180 keV and 420 A/cm 2 , respectively. The focusing angle of the ionbeams was 4.3deg. The beam brightness was estimated to be 1.3 GW/cm 2 ·rad 2 . The focusing distance of the ionbeams was found to be controllable by changing the diameters of the anode and cathode. (author)

Full Text Available An electron beamion source (EBIS will be constructed and used to charge breed ions from the californium rare isotope breeder upgrade (CARIBU for postacceleration into the Argonne tandem linear accelerator system (ATLAS. Simulations of the EBIS charge breeder performance and the related ion transport systems are reported. Propagation of the electron beam through the EBIS was verified, and the anticipated incident power density within the electron collector was identified. The full normalized acceptance of the charge breeder with a 2 A electron beam, 0.024π mm mrad for nominal operating parameters, was determined by simulating ion injection into the EBIS. The optics of the ion transport lines were carefully optimized to achieve well-matched ion injection, to minimize emittance growth of the injected and extractedionbeams, and to enable adequate testing of the charge bred ions prior to installation in ATLAS.

Ion irradiation of crystalline solids leads not only to defect formation and amorphization but also to mechanical stress. In the past, many investigations in various materials were performed focusing on the ionbeam induced damage formation but only several experiments were done to investigate the ionbeam induced stress evolution. Especially in microelectronic devices, mechanical stress leads to several unwanted effects like cracking and peeling of surface layers as well as changing physical properties and anomalous diffusion of dopants. To study the stress formation and relaxation process in semiconductors, crystalline and amorphous germanium samples were irradiated with 3 MeV iodine ions at different ion fluence rates. The irradiation induced stress evolution was measured in situ with a laser reflection technique as a function of ion fluence, whereas the damage formation was investigated by means of Rutherford backscattering spectrometry. The investigations show that mechanical stress builds up at low ion fluences as a direct consequence of ionbeam induced point defect formation. However, further ion irradiation causes a stress relaxation which is attributed to the accumulation of point defects and therefore the creation of amorphous regions. A constant stress state is reached at high ion fluences if a homogeneous amorphous surface layer was formed and no further ionbeam induced phase transition took place. Based on the results, we can conclude that the ionbeam induced stress evolution seems to be mainly dominated by the creation and accumulation of irradiation induced structural modification.

It is well known that ionbeams play an important role in semiconductor industry, which utilizes ion implantation and irradiation for materials modification. Ion sputtering technique is used to fabricate multifunctional coatings and multilayers. Using ion implantation, there is a continued effort for fabrication of quantum bit structures for future quantum computers. Availability of focused ionbeams (FIBs) has widened the applications of ionbeams and nanostructured functional materials are being fabricated using FIBs. Various quantum structures can be fabricated using FIB. Ferromagnetism can either be induced or destroyed in special layered structures using ion irradiation. The magnetic exchange bias phenomenon is of tremendous utility in magnetic recording. Issues of lateral diffusion in nanoscale doping of semiconductors by FIB and an example of exchange bias enhancement by ion irradiation are discussed.

We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ionbeam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H{sub 2}O and O{sub 2}. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances.

We study the possibility of obtaining liquid or crystalline ordered structures in a cooled heavy ionbeam in a storage ring. First the structure of very cold ions confined in a cylindrically symmetric static potential is explored by means of molecular dynamics calculations. Liquid like structures are obtained for the ratio of average Coulomb to thermal energies and Γ ≅ 10 and crystalline structures like strings, zigzags, helices, tetrehedra, intertwined helices, polygons, etc. emerge for Γ > 25. For larger densities, the particles arrange in cylindrical shells and form equilateral triangles on their surfaces arranged in hexagons which are characteristic of two-dimensional Coulomb solids. The molecular dynamics results are compared to results of energy minimization of these structures or of geometrical models. Realistic molecular dynamics calculations in the lattice of the Experimental Storage Ring at GSI Darmstadt including the effects of the bending, focussing and defocussing magnets, of the free sections and of the electron cooler revealed that such structures at higher densities are easily destroyed by heating through shearing forces. Therefore the dynamics of the simple Coulomb string is explored in more detail. The potential energy for large amplitude longitudinal and transverse vibrations is calculated and the dispersion relations and response functions in the harmonic limit are given and possible excitation mechanisms are discussed. (orig.)

The initial motivation for the development of IonBeam Sputtering (IBS) processes was the need for optical coatings with extremely low optical scatter losses for laser gyros. Especially, backscattering of the gyro-mirrors couples the directional modes in the ring resonator leading to the lock in effect which limits the sensitivity of the gyro. Accordingly, the first patent on IBS was approved for an aircraft company (Litton) in 1978. In the course of the rapid development of the IBS-concept during the last two decades, an extremely high optical quality could be achieved for laser coatings in the VIS- and NIR-spectral region. For example, high reflecting coatings with total optical losses below 1 ppm were demonstrated for specific precision measurement applications with the Nd:YAG-laser operating at 1.064 μm. Even though the high quality level of IBS-coatings had been confirmed in many applications, the process has not found its way into the production environment of most optical companies. Major restrictions are the relatively low rate of the deposition process and the poor lateral homogeneity of the coatings, which are related to the output characteristics of the currently available ion sources. In the present contribution, the basic principles of IBS will be discussed in the context of the demands of modern laser technology. Besides selected examples for special applications of IBS, aspects will be presented for approaches towards rapid manufacturing of coatings and the production of rugate filters on the basis of IBS-techniques.

An intense electron beam is extracted without space charge limit from a dc plasma source along a magnetic field. The beam space charge is neutralized stably through back streaming of self-ionized ions from the beamextracting anode region where a neutral gas is fed locally. In Appendix I, a space charge free electron gun is designed under this neutralization method. In Appendix II, a dynamic discharge through a series resistance is described, where an operative mechanism of the well-known TP-D plasma is clarified. (auth.)

Radioactive IonBeams (RIBs) at the Holifield Radioactive IonBeam Facility (HRIBF) are produced using the isotope separation on-line technique and are subsequently accelerated up to a few MeV per nucleon for use in nuclear physics experiments. The first RIB experiments at the HRIBF were completed at the end of 1998 using sup 1 sup 7 F beams. Since then other proton-rich ionbeams have been developed and a large number of neutron-rich ionbeams are now available. The neutron-rich radioactive nuclei are produced via proton-induced fission of uranium in a low-density matrix of uranium carbide. Recently developed RIBs include sup 2 sup 5 Al from a silicon carbide target and isobarically pure beams of neutron-rich Ge, Sn, Br and I isotopes from a uranium carbide target.

In our light ion inertial confinement fusion (ICF) program, fusion capsules are driven with an intense x-ray radiation field produced when an intense beam of ions penetrates a radiation case and deposits energy in a foam x-ray conversion region. A first step in the program is to generate and measure these intense fields on the Particle Beam Fusion Accelerator II (PBFA II). Our goal is to generate a 100-eV radiation temperature in lithium ionbeam driven hohlraums, the radiation environment which will provide the initial drive temperature for ionbeam driven implosion systems designed to achieve high gain. In this paper, we describe the design of such hohlraum targets and their predicted performance on PBFA II as we provide increasing ionbeam intensities

We have developed off-line experimental techniques and apparatuses that permit direct measurement of effusive-flow delay times and ionization efficiencies for nearly any chemically reactive element in high-temperature target/ion sources (TIS) commonly used for on-line radioactive ion-beam (RIB) generation. The apparatuses include a hot Ta valve for effusive-flow delay-time measurements, a cooled molecular injection system for determination of ionization efficiencies, and a gas flow measurement/control system for introducing very low, well-defined molecular flows into the TIS. Measurements are performed on a test stand using molecular feed compounds containing stable complements of the radioactive nuclei of interest delivered to the TIS at flow rates commensurate with on-line RIB generation. In this article, the general techniques are described and effusive-flow delay times and ionization efficiency measurements are reported for fluorine in an electron-beam plasma target/ion source developed for RIB generation and operated in both positive- and negative-ionextraction modes. copyright 1998 American Institute of Physics

Full text: Particle beams are finding increasing application in material sciences and the interest covers both applied as well as fundamental investigations. In the present talk application of electron and ionbeams in several polymers such as polysilanes, polystyrene, polyolefins, polymethylmethacrylates and related polymers will be presented. It includes among other investigations (such as product analysis) pulse radiolysis studies and effect of LET on polymers. Importance of positron studies in material sciences especially bulk polymers is well documented. A relatively new technique, namely, positron beam application especially in thin film polymers is a new and emerging areas. The interest ranges from applied aspects as well as fundamental understanding of surfaces and interfaces. The present talk will detail the development of a pulsed positron beam using LINAC at Institute of Scientific and Industrial Research (ISIR) as well as its applications to polymer thin films

Subsurface (amorphous-crystalline interface) structure of keV ionbeam modified Si(001) wafers was studied for the first time using non-destructive technique and compared with that of the top one. Ion-beam modifications of the Si samples were done using state-of-art high-current ion implanter facility at Saha Institute of Nuclear Physics by changing energy, dose and angle of incidence of the Ar + ionbeam. To bring out the underlying modification depth-resolved x-ray grazing incidence diffraction has been carried out using synchrotron radiation facility, while the structure of the top surface was studied through atomic force microscopy

The linear theory of the electromagnetic ionbeam instability for arbitrary angles of propagation has been studied. The parameters considered in the theory are typical of the solar wind upstream of the earth's bow shock when a 'reflected' proton beam is present. Maximum growth occurs for propagation parallel to the ambient field B, but this instability also displays significant growth at wave-vectors oblique to B, Oblique, unstable modes seem to be the likely source of the compressive magnetic fluctuations recently observed in conjunction with 'diffuse' ion population. An energetic ionbeam does not directly give rise to linear growth of either ion acoustic or whistler mode instabilities

Negative lithium ions (Li - ) were extracted from a 6-cm-diam 7-cm-long negative hydrogen ion (H - ) source to simulate the condition of Li - extraction from a Li vapor introduced ion source for the neutral beam heating. The amount of the Li - current extracted from a hydrogen plasma with Li vapor was comparable to that extracted from a pure Li plasma. However, the amount of the H - current decreased as the H 2 gas pressure in the source decreased due to a getter-pump effect of Li during the introduction of Li vapor. A heat shield installed to keep a high wall temperature was effective in mitigating the pressure decrease. However, the H - current extracted from the ion source equipped with the heat shield became 20% of the original value, as Li vapor was injected into the ion source. copyright 1996 American Institute of Physics

The present status of the experimental facility consisting of a heavy ionbeam travelling through a laser created plasma target is described. Some aspects such as laser-tandem coupling, beam performances, constraints on the plasma parameter ranges, plasma and beam diagnostics are analyzed

A new design of a broad beam RF ion source is made to be capable to deliver wide and uniform beam with currents reaching (100 {mu} A up to 30 mA) at extraction voltages (200 V up to 2 kV). Its plasma intensifying system is made with the addition of electrons from an immersed filament in the discharge and axial magnetic field (70 up to 300 G). A uniform beam distribution is made with a planner graphite cathode which has a number of holes arranged to produce perveance matching with the normal Gaussian distribution of the beam density. These holes are arranged in a consequent orbits with equal distance between the adjacent holes in each orbit. These holes increase in diameter with increasing the orbit radius. This allows increasing the extractedion currents at the source outer edges and decreases its value at the source inner region; producing wide and uniform beam which is suitable for material modifications. The beam profiles are traced with electromechanical scanner and X-Y recorder. The perveance matching is found to produce a beam uniformity of =66% of its width which reaches =6 cm. The variation of the output currents are with the variation of extraction voltages, magnetic field, discharge pressure and electron injection into the plasma. The extracted current increases with the increase of the discharge pressure, RF power and magnetic field intensity. The influence of electron plasma interaction is found to have a great effect on increasing the ion currents to about four times its value without electron interaction, however, this increase is limited due to presence of breakdown at V{sub ex} > 2 kV. The simple design of this source, its cleanness due to the use of pyrex discharge bottle, easy operation and maintenance adds other features to this broad beam type ion source which makes it suitable for metallurgical applications in broad beam accelerators. 6 figs.

The physical mechanism of the formation of the negative ionbeam halo and the heat loads of the multi-stage acceleration grids are investigated with the 3D PIC (particle in cell) simulation. The following physical mechanism of the beam halo formation is verified: The beam core and the halo consist of the negative ionsextracted from the center and the periphery of the meniscus, respectively. This difference of negative ionextraction location results in a geometrical aberration. Furthermore, it is shown that the heat loads on the first acceleration grid and the second acceleration grid are quantitatively improved compared with those for the 2D PIC simulation result.

A high current low emittance high charge state heavy ionbeam source is being developed. This is designed to deliver HIF (heavy ion fusion) driver accelerator scale beam. Using high-charge-state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system which consists of the gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 2D beam envelope simulations and experimental feasibility studies' results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector

Beamion loss from the Compact Helical System (CHS) has been measured with a scintillator-type probe. The total loss to the probe, and the pitch angle and gyroradius distributions of that loss, have been measured as various plasma parameters were scanned. Three classes of beamion loss were observed at the probe position: passing ions with pitch angles within 10o of those of transition orbits, ions on transition orbits, and ions on trapped orbits, typically 15o or more from transition orbits. Some orbit calculations in this geometry have been performed in order to understand the characteristics of the loss. Simulation of the detector signal based upon the following of orbits from realistic beam deposition profiles is not able to reproduce the pitch angle distribution of the losses measured. Consequently it is inferred that internal plasma processes, whether magnetohydrodynamic modes, radial electric fields, or plasma turbulence, move previously confined beamions to transition orbits, resulting in their loss.

Under a framework of JAERI-KEK joint project of high intensity proton accelerator, as for research and develop of the accelerator driven nuclear transmutation of the long lived radioactive nuclide, it is planed to built the Transmutation Physics Experiment Facility (TEF-P) and the Transmutation Engineering Experiment Facility (TEF-E). The TEF-P is used for the experiments for subcritical system coupled with a spallation neutron target bombarded with 600-MeV proton beam accelerated by the LINAC. To limit the maximum thermal power less than 500 W at the TEF-P, an incident beam power should be less than 10 W. On the contrary, at the TEF-E, high power beam of 200 kW is requested. Both high and low power beams are demanded for the transmutation facilities. It is difficult to deliver a low power beam to the TEF-P. Conventional beamextraction technique with a thin foil, is not desirable because the scattering of the beam at the foil requires the massive shield. Therefore, we study a new technique to extract a small portion of the beam precisely from the high intensity beam by using a laser beam. By a laser beam, H{sup -} in the beam from LINAC is partially changed to H{sup 0} beam so that a low current H{sup 0} beam can be obtained. As the cross section of the charge exchange reaction for H{sup -} ions has a peak around at a wave length of 1 {mu}m for photons, YAG laser is suitable for this charge exchange because of its 1.06 {mu}m wave length. It is derived that 10 W beam for 600-MeV proton can be extracted by the YAG laser with power of 2 J for each pulse of 25 Hz. By this technique, the pulse width for the extractedbeam can be controlled by changing the time width of laser irradiation. When a charge exchanger having the beam collide point existing in straight section, a background beam current of projectile, however, will be increased due to the interaction with the residual gas in the beam duct. Thus, a charge exchanger is devised having the beam collide point in a

In order to improve the time structure of slow extractedbeam spill for the KEK 12GeV PS, the spill control system has been upgraded by adding feed forward signal to feedback signal. Further, the wake field in the RF cavity has been cancelled by the beam bunch signal to reduce the re-bunch effect during extraction period. (author)

An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ionbeams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ionbeams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ionbeam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beamextracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems.

Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems

A simple model for ionextraction from a plasma is analyzed. The order of magnitude of the plasma parameters leads to a singular perturbation problem for a semilinear elliptic equation. We first prove existence of solutions for the perturbed problem and uniqueness under certain conditions. Then we prove the convergence of these solutions, when the parameters go to zero, towards the solution of a Child-Langmuir problem

In solvent extraction separation of metal ions, recently, many researchers have investigated possible use of hydrophobic ionic liquids as extraction media instead of organic solvents. Ionic liquids are salts of liquid state around room temperature and can act not only as solvents but also as ion-exchangers. Therefore, the extraction mechanism of metal ions into ionic liquids is complicated. This review presents current overview and perspective on evaluation of nature of hydrophobic ionic liquids as extraction media for metal ions.

A dc negative hydrogen and/or deuterium ion source is needed to prouce high-power, high-energy neutral beams for alpha diagnostics and current drive applicatiosn in fusion devices. The favorable beam particle energy for such applications extends to 1.5 MeV/amu. Continuous-wave (cw) radio-frequency quadrupole (RFQ) accelerators have been proposed to accelerate negative ions effeciently to this energy range. In this paper, the desired beam properties for ionbeams injected into cw RFQ accelerators are summariezed. A number of candidate ion sources being developed at Culham, JAERI, LBL, and ORNL may prove useful for these applications. The properties of the Volume Ionization with Transverse Extraction (VITEX) ion sources being developed at ORNL are presented. Scaling such a dc ion source to produce ampere beams is discussed. 53 refs., 4 figs., 2 tabs

A dc negative hydrogen and/or deuterium ion source is needed to produce high-power, high-energy neutral beams for alpha diagnostics and current drive applications in fusion devices. The favorable beam particle energy for such applications extends to 1.5 MeV/amu. Continuous-wave (cw) radiofrequency quadrupole (RFQ) accelerators have been proposed to accelerate negative ions efficiently to this energy range. In this paper, the desired beam properties for ionbeams injected into cw RFQ accelerators are summarized. A number of candidate ion sources being developed at Culham, JAERI, LBL, and ORNL may prove useful for these applications. The properties of the Volume Ionization with Transverse Extraction (VITEX) ion sources being developed at ORNL are presented. Scaling such a dc ion source to produce ampere beams is discussed. 53 refs., 4 figs., 2 tabs

The physicists of the CERN heavy ion community (SPS fixed target physics) have requested lighter ions than the traditional lead ions, to scale their results and to check their theories. Studies have been carried out to investigate the behaviour of the ECR4 for the production of an indium beam. Stability problems and the low melting point of indium required some modifications to the oven power control system which will also benefit normal lead ion production. Present results of the source behaviour and the ionbeam characteristics will be presented.

We have used the Electron BeamIon Trap at LLNL to study dielectronic recombination in highly charged ions. Our technique is unique because we observe the x-rays from dielectronic recombination at the same time we see x-rays from all other electron-ion interactions. We have recently taken high-resolution, state-selective data that resolves individual resonances

Keywords. RIKEN; radioactive ionbeams; magic numbers. PACS No. 21.10.-k. 1. Introduction. In RIKEN, there are several heavy ion accelerators. Main accelerator is the RIKEN ring cyclotron (RRC) with K = 540, that has been operated from 1986. The RRC has two injectors; one is heavy ion linear accelerator that has been ...

The 2-D code for simulating of ion optics system of positive ionextraction from a plasma source is described. Example calculation of 100 kV optics for the extractionion IHEP gun is presented. The trajectories of particles and emittance plots are resulted. The aberrations influ-ence strongly on ion optics for considered geometry.

A high current density (≈3 mA/cm{sup 2}) hydrogen ionbeam source operating in an extremely low-energy region (E{sub ib} ≈ 150–200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E{sub ib} is being reduced. The radial profiles of the ionbeam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extractedbeamions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beamions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beamion space charge.

A quasi-steady-state ion source has been developed for neutral beam injection applications. It is of the duoPIGatron type designed for delivering 50 A of hydrogen ions at 80 keV for 30-s-long pulses. Ionbeams of 40 A at 75 keV were extracted for pulse lengths up to 30 s, maintaining excellent optical quality in the beam for the entire pulse duration. The design features and operational characteristics of the ion source are elaborated

A new analytic model is presented which accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy-ionbeam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well to exact solutions of Poisson's equation. Field values are shown for several simple beam profiles and are compared with values obtained from simpler models

Heavy ionbeams with initially uniform line charge density can be compressed longitudinally by an order of magnitude in such a way that the compressed beam has uniform line charge density and velocity-tilt profiles. There are no envelope mismatch oscillations during compression. Although the transverse temperature varies along the beam and also varies with time, no substantial longitudinal and transverse emittance growth has been observed. Scaling laws for beam radius and transport system parameters are given

Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ionbeams in biotechnology and biomedicine. Although the ionbeam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ionbeam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ionbeams in biotechnology and biomedicine. Although the ionbeam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ionbeam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

Track-etched detectors (TED) have been used as linear energy transfer (LET) spectrometers in heavy ionbeams for many years. LET spectra and depth -dose distribution of a carbon ionbeam were measured behind polymethylmethacrylate degraders at Heavy Ion Medical Accelerator in Chiba, Japan. The measurements were performed along monoenergetic beam with energy 290 MeV u -1 in different positions: (1) at beamextraction area, (2) at beginning, (3) maximum and (4) behind the Bragg peak region (0, 117, 147 and 151 mm of water-equivalent depth, respectively). The LET spectra inside and outside of the primary ionbeam have been evaluated. TED record only heavy charged particles with LET above 8 -10 keV μm -1 , while electrons and ions with lower LET are not detected. The Geant4 simulation toolkit version 4.9.6.P01 has been used to estimate the contribution of non-detected particles to absorbed dose. Presented results demonstrate the applicability of TED for microdosimetry measurements in therapeutic carbon ionbeams. (authors)

A magnetically insulated ion diode with an active ion source of a gas puff plasma gun has been developed in order to generate a high-intensity pulsed heavy ionbeam for the implantation process of semiconductors and the surface modification of materials. The nitrogen plasma produced by the plasma gun is injected into the acceleration gap of the diode with the external magnetic field system. The ion diode is operated at diode voltage approx. =200 kV, diode current approx. =2 kA and pulse duration approx. =150 ns. A new acceleration gap configuration for focusing ionbeam has been designed in order to enhance the ion current density. The experimental results show that the ion current density is enhanced by a factor of 2 and the ionbeam has the ion current density of 27 A/cm 2 . In addition, the coaxial type Marx generator with voltage 200 kV and current 15 kA has been developed and installed in the focus type ion diode. The ionbeam of ion current density approx. =54 A/cm 2 is obtained. To produce metallic ionbeams, an ion source by aluminum wire discharge has been developed and the aluminum plasma of ion current density ∼70 A/cm 2 is measured. (author)

The nearly endless variety of interesting and challenging problems makes physics research enjoyable. Most of us would choose to be physicists even if physics had no practical applications. However, physics does have practical applications. This workshop deals with one of those applications, namely ionbeam fusion. Not all interesting and challenging atomic physics questions are important for ionbeam fusion. This paper suggests some questions that may be important for ionbeam fusion. It also suggests some criteria for determining if a question is only interesting, or both interesting and important. Importance is time dependent and, because of some restrictions on the flow of information, also country dependent. In the early days of ionbeam fusion, it was important to determine if ionbeam fusion made sense. Approximate answers and bounds on various parameters were required. Accurate, detailed answers were not needed. Because of the efforts of many people attending this workshop, we now know that ionbeam fusion does make some sense. We must still determine if ionbeam fusion truly makes good sense. If it does make good sense, we must determine how to make it work. Accurate detailed answers are becoming increasingly important. (author)

Gabor or plasma lenses have previously been used to focus intense beams of positive ions at energies from 10 keV to 5 MeV. It is the large electrostatic field of the non-neutral plasma in the Gabor lens which is responsible for the focusing. Focusing an ionbeam with a given sign of charge in a Gabor lens requires a non-neutral plasma with the opposite sign of charge as the beam. A Gabor lens constructed at Fermilab has been used to focus a 30 keV proton beam with good optical quality. We discuss studies of the action of a Gabor lens on a beam of negative ions. A Gabor lens has been considered for matching an H/sup /minus// beam into an RFQ in the redesign of the low energy section of the Fermilab linac. 9 refs., 3 figs., 1 tab

Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ionbeam accelerator. The 0.3 MeV, 30-mA K + beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ionbeam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multi-channel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (VISAR), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.

A collimating grid for an ion source located after the exit grid. The collimating grid collimates the ion beamlets and disallows beam spread and limits the beam divergence during transients and steady state operation. The additional exit or collimating grid prevents beam divergence during turn-on and turn-off and prevents ions from hitting the periphery of the target where there is re-deposited material or from missing the target and hitting the wall of the vessel where there is deposited material, thereby preventing defects from being deposited on a substrate to be coated. Thus, the addition of a collimating grid to an ion source ensures that the ionbeam will hit and be confined to a specific target area.

Kinetic energy distribution of ionbeams was measured by a retarding field energy analyzer for a mass-selective cluster ionbeam deposition system that uses a quadrupole ion trap as a cluster ionbeam source. The results indicated that the system delivers a cluster-ionbeam with energy distribution of approx 2 eV, which corresponded well to the calculation results of the trapping potentials in the ion trap. Using this deposition system, mass-selected hydrogenated Si cluster ions Si sub n H sub x sup + were actually deposited on Si(111)-(7x7) surfaces at impact kinetic energy E sub d of 3-30 eV. Observation by using a scanning tunneling microscope (STM) demonstrated that Si sub 6 H sub x sup + cluster ions landed on the surface without decomposition at E sub d =3 eV, while the deposition was destructive at E sub d>=18 eV. (author)

Ion optics considerations on the granty-like beam delivery system for light-ion cancer therapy are presented. A low-angle active beam scanning in two directions is included in the preliminary gantry design. The optical properties of several gantry modifications are discussed. (orig.)

Highlights: • ELISE is the first step in the European roadmap for the development of the ITER NBI. • Several beam diagnostic tools have been installed, the latest results are presented. • A gaussian fit procedure has been implemented to characterize the large ionbeam. • Average beamlet group inhomogeneity is maximum 13%, close to the ITER target of 10%. • Beam divergence measured by calorimeter agrees with the BES measurements within 30%. - Abstract: The test facility ELISE is the first step within the European roadmap for the development of the ITER NBI system. ELISE is equipped with a 1 × 0.9 m"2 radio frequency negative ion source (half the ITER source size) and an ITER-like 3-grid extraction system which can extract an H"− or D"− beam for 10 s every 3 min (limited by available power supplies) with a total acceleration voltage of up to 60 kV. In the beam line of ELISE several beam diagnostic tools have been installed with the aim to evaluate beam intensity, divergence and uniformity. A copper diagnostic calorimeter gives the possibility to measure the beam power density profile with high resolution. The measurements are performed by an IR micro-bolometer camera and 48 thermocouples embedded in the calorimeter. A gaussian fit procedure has been implemented in order to characterize the large negative ionbeam produced by ELISE. The latest results obtained from the beam calorimetry at ELISE show that the average beamlet group inhomogeneity is maximum 13%. The measured beam divergence agrees with the one measured by beam emission spectroscopy within 30%.

Ionbeam analysis methods have been applied to the study of technologically important issues in III-V nanometre structure science. In the first application, the incorporation of hydrogen in GaAs during electron cyclotron resonance etching was studied using the {sup 1}H({sup 15}N,{alpha}{gamma}){sup 12}C reaction analysis method. The major part of the work was carried out using mass and energy dispersive Recoil Spectrometry (RS). RS was used to study reactions of thin metal films InP reactions. The metals investigated include Cr, Ti, Ni, Pd and Pt and the reactions as a function of temperature were studied to elucidate suitable compounds for contacts and metallization. Using {sup 127}I in the 0.5A to 0.7A MeV region as the projectile, the depth profiles for the different elements were obtained. Complementary measurements with X-ray diffraction to obtain chemical phase information as well as scanning electron microscopy to study the surface morphology were also carried out. 59 refs, 15 figs.

Ionbeam analysis methods have been applied to the study of technologically important issues in III-V nanometre structure science. In the first application, the incorporation of hydrogen in GaAs during electron cyclotron resonance etching was studied using the 1 H( 15 N,αγ) 12 C reaction analysis method. The major part of the work was carried out using mass and energy dispersive Recoil Spectrometry (RS). RS was used to study reactions of thin metal films InP reactions. The metals investigated include Cr, Ti, Ni, Pd and Pt and the reactions as a function of temperature were studied to elucidate suitable compounds for contacts and metallization. Using 127 I in the 0.5A to 0.7A MeV region as the projectile, the depth profiles for the different elements were obtained. Complementary measurements with X-ray diffraction to obtain chemical phase information as well as scanning electron microscopy to study the surface morphology were also carried out. 59 refs, 15 figs

During the last few years, substantial work has been done and interest developed in the scientific opportunities available with accelerated radioactive ionbeams (RIBs) for nuclear physics, astrophysics, and applied research. This interest has led to the construction, development, and proposed development of both first- and second-generation RIB facilities in Asia, North America, and Europe; international conferences on RIBs at Berkeley and Louvain-la-Neuve; and many workshops on specific aspects of RIB production and science. This paper provides a discussion of both the projectile fragmentation, PF, and isotope separator on-line, ISOL, approach to RIB production with particular emphasis on the latter approach, which employs a postaccelerator and is most suitable for nuclear structure physics. The existing, under construction, and proposed facilities worldwide are discussed. The paper draws heavily from the CERN ISOLDE work, the North American IsoSpin Laboratory (ISL) study, and the operating first-generation RIB facility at Louvain-la-Neuve, and the first-generation RIB project currently being constructed at ORNL

Irradiation of solids with energetic particles results in the reorganization of constituent target atoms, i.e., ionbeam mixing (IM). At low temperatures, IM is characterized by prompt (10 -10 s) diffusion processes which are localized in the vicinity of the displacement cascade. Mixing at low temperatures can cause the system to depart far from the equilibrium state. At elevated temperatures, the diffusion of radiation-induced defects extends the mixing to longer times and greater distances. These delayed IM processes tend to return the system toward equilibrium. Recent experimental progress has led to a qualitative understanding of the fundamental aspects of IM in both temperature regimes. This has been achieved through systematic measurements of the influences of temperature, dose, dose-rate, cascade energy density, and chemical interactions on IM. The results of these experiments will be reviewed and compared to IM models based on collisional, thermal spike, and radiation-enhanced diffusion processes. The relation of IM to other fundamental radiation damage effects will also be discussed. 75 refs., 8 figs., 2 tabs

The edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, as it can greatly reduce the key performance of the optical system. Ionbeam figuring (IBF) has the advantage of no edge effect, so we can use it to remove high points on the edge and improve surface accuracy. The edge local correction method (ELCM) of IBF processes only the surface edge zone, and is very different from the current full caliber figuring method (FCFM). Therefore, it is necessary to study the ELCM of IBF. In this paper, the key factors of ELCM are analyzed, such as dwell time algorithm, edge data extension methods, and the outward dimension of the starting figuring point. At the same time, the distinctions between ELCM and FCFM are compared. Finally, a 142 mm diameter fused silica mirror is fabricated to verify the validity of the theoretical of ELCM. The experimental results indicate that the figuring precision and efficiency can be obviously improved by ELCM.

Pellet fusion, driven by nanosecond pulses containing α particles with 200 MeV energy, is being developed as a neutron source. A prototype system is in the conceptual design stage. During the coming year, engineering design of required accelerator components, storage rings, and pellet configurations, as well as experiments on energy deposition mechanisms, should be accomplished. Successful construction and tests of prototype rings, followed by two years of full scale system construction, would give a source producing a useful flux of fusion neutrons for materials testing. The system as currently envisioned would employ 100 small superconducting high field storage rings (15 cm radius, 140 kG field) which would be synchronously filled with circulating 1 nsec pulses from a 200 MeV linear accelerator over a period of 3 x 10 -4 sec. These ion pulses would all be simultaneously extracted, forming a total current of 10 kA, and focussed from all directions on a deuterium and tritium (DT) pellet with 0.17 mm radium, surrounded by a heavier (metal) coating to increase confinement time and aid compression efficiency. The overall repetition rate, limited principally by physical transport of the pellets, could reach 100/sec. Spacing between pellet and focussing elements would be about 1 m. The predominant engineering problems are the fast extraction mechanism and beam transport devices for the storage rings. Additional theoretical and experimental studies are required on the crucial energy deposition and transport mechanisms in pellets with ionbeam heating before firm estimates can be given. Preliminary estimates suggest fusion neutron yields of at least 10 14 /sec and possibly 10 16 /sec are possible, with optimal pellet dynamics, but without the necessity for any large advances in the state-of-the-art in accelerator and storage ring design. (auth)

Inorganic scintillation screens are a common diagnostics tool in heavy ion accelerators. In order to investigate the imaging properties of various screen materials, four different material compositions were irradiated at GSI, using protons up to Uranium ions as projectiles. Beams were extracted from SIS18 with high energy (300 MeV/u) in slow and fast extraction mode. During irradiation the scintillation response of the screens was simultaneously recorded by two different optical setups to investigate light output, profile characteristics and emission spectra. It was observed, that fast extractedbeams induce in general lower light output than slow extractedbeams, while the light output per deposited energy decreases with atomic number. The analysis of the spectral emission as well as investigations with classical optical methods showed no significant defect-building in all materials, not even under irradiation with increasing beam intensity or over long time periods. The investigated scintillation screens can be considered as stable under irradiation with high energetic heavy ion pulses and are appropriate for beam diagnostics applications in future accelerator facilities like FAIR. Characteristic properties and application areas of the screens are presented in the poster.

An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ionbeam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ionbeam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.

The first experimental study is reported of a plasma produced by a heavy-ionbeam. Relevant parameters for heating with heavy ions are described, temperature and density of the plasma are determined, and the hydrodynamic motion in the target induced by the beam is studied. The measured temperature and the free-electron density are compared with a two-dimensional hydrodynamic-model calculation. In accordance with the model, a radial rarefaction wave reaching the center of the target was observed and the penetration velocity of the ionbeam into the xenon-gas target was measured

Beamion loss measurements from Compact Helical System (CHS) plasmas under a variety of conditions show a strong loss of ions in the range of pitch angles corresponding to transition orbits at the probe location. A numerical model has been developed which includes the beamion orbits, and details of the detector, plasma, vessel, and neutral beam geometry. From this, the expected classical (i.e. collisionless single particle orbit) signal at the detector can be computed. Preliminary comparisons between the experimental data and model predictions indicate that the classical behavior of the orbits and the machine geometry are insufficient to explain the observations. (author)

A radiofrequency quadrupole (RFQ) ion accumulator and buncher has been designed for the low-energy beam and ion-trap (LEBIT) facility which is being set up at the NSCL/MSU. The LEBIT buncher will be a cryogenic system. Compared to room-temperature systems an improved beam quality and overall efficiency are expected. It will feature a novel electrode structure with a drastically reduced number of electrodes for simplified operation. Its design is presented and Monte-Carlo type ion-trajectory calculations are discussed which predict excellent beam quality and high performance

A radiofrequency quadrupole (RFQ) ion accumulator and buncher has been designed for the low-energy beam and ion-trap (LEBIT) facility which is being set up at the NSCL/MSU. The LEBIT buncher will be a cryogenic system. Compared to room-temperature systems an improved beam quality and overall efficiency are expected. It will feature a novel electrode structure with a drastically reduced number of electrodes for simplified operation. Its design is presented and Monte-Carlo type ion-trajectory calculations are discussed which predict excellent beam quality and high performance.